Archive for the 'techsup' Category

Updated: How to fix a reassigned C:/ drive letter

Thursday, February 4th, 2010

More than two years after I wrote this first blog entry dealing with the subject, having come up against this problem time and time again without being able to fix it, I went and did some experimenting on a PC at work to see if I could find a solution.

Short version: Instead of trying to swap the drive letters around by renaming the \DosDevices\ registry keys, I’ve discovered that if you delete the lot of them, Windows will recreate them when it next boots (as many of them as you have discrete disk drives plugged in at the time), and on the machine I tried it at work today it worked flawlessly: it reassigned the boot drive as C:\, the CD drive as D:\, the four card reader slots as E:\ through H:\ and everything was fixed.

Longer, more helpful version: If you’ve just added a hard drive to your PC (typical scenario: it’s the ex boot drive of an older PC you’ve just decomissioned, and you want the data off your old XP install) and Windows no longer boots, getting stuck instead just before the welcome screen with just the windows XP logo showing and no “Please wait” text below it, it’s very likely that XP’s suddenly developed an identity crisis of sorts and is referring to the new drive as C:\. It’s stupid, really quite illogical, and basically poleaxes that install unless you’re willing to play chicken with the registry.

Fortunately, this game of chicken is reasonably tried and true, and it’s easy enough to figure out if you’ve got even a bit of technical familiarity with your PC (as you probably are if you’ve just opened it and plugged another hard drive into it).

Hit Windows + R to bring up the Run dialog (probably you can also get to it by clicking your Start menu and then “Run…”), type regedit and hit enter. This will load the Registry Editor, which is basically a precision scope that lets you look inside your operating system’s brain. This particular registry key – HKEY_LOCAL_MACHINE / SYSTEM / MountedDevices – lists the mapping between various disk drives on your computer and their respective drive letters as visible in My Computer.

What happens is that it sometimes gets confused about how to refer to your boot volume, and if your boot volume’s drive letter changes after you install XP, it will probably get stuck partway through starting up and hang just before the Welcome/login screen.

The information here might also be of interest/use to you if that drive letter was D:\ or E:\ or something else other than C:\ from the moment you installed XP, and you want to change it back to C:\ without having to reinstall again.

The fix: Deleting each of the \DosDevices\ values shown in the registry in the above screenshot will cause Windows to recreate and reassign the drive letters in your computer. If XP’s not booting anymore, obviously you can’t just run regedit like above, but there are ways around it. There do exist commandline tools you could run from a floppy disk or something, but by far the easiest way is to grab a registry-editing liveCD of some sort. I use Mini XP on Hiren’s BootCD, but this tool should do the trick easily enough for most.

This procedure has so far worked to bring Windows XP back to life on both a customer’s PC at my work, and on my own laptop at home (on which I dualboot XP and 7 for just this sort of messing about). If you try this method, leave a comment or email me and let me know how it went!

Update 10/2: If you have programs installed to drive letters other than C:\, be aware this could wreak havoc with those. Windows may be intelligent enough to reassign the driver letters with respect to installed programs, or it may not be. I haven’t tested this, and being a rare set of circumstances I doubt I’ll ever have the opportunity to. Your best bet in that situation would be trying the old manual renaming method. Remember you could delete the DosDevices entries to fix things enough to make it bootable again, and then swap drive letters D+ to your heart’s content to get your other programs to work without reinstalling those.

Uninstalling Trend Micro without the password

Wednesday, February 3rd, 2010

A customer at work wanted me to take Trend Micro Internet Security off his PC. The only problem was someone’d helpfully password-protected Trend, and nothing could be done without the magic word. After some fruitless googling, I gave up and called Trend Micro Australia for help.

I’d long considered this a last resort for any problem, but was pleasantly surprised with the outcome. The guy I spoke to asked for my name and the serial number of my product. I said I didn’t have the serial number, but went on and explained my problem to him.

Far from refusing to help me without that little bit of information (I’ve been hung up on by tech support from other companies for not precisely following their rulebook), the fellow immediately latched onto the problem and told me to Start -> Run -> tissuprt, which is a kind of maintenance program for Trend products. It provided a very simple GUI with a button to uninstall all Trend products from the PC without requiring the password. Exactly what I (and probably you googlers) needed.

I mentioned to him the trouble I’d had in finding out how to do this, and he said it’s actually on their website, plain as day for anybody to read. He helpfully emailed me the link, and here it is.

Full marks to the company for the phone support, but the reason I couldn’t find that page in the first place is because nowhere on it does it have the word “password”. Go look, I’m not kidding. Nobody who’s needed this information has been able to find it, because inevitably their search is phrased around not having that password.

Anyway. Hope tissuprt helps somebody.

Howto: Edit the boot menu easily in Windows Vista and 7

Saturday, September 19th, 2009

Startup options in Windows XP. Startup options in Windows 7.

The Windows XP boot menu is determined by the contents of C:\boot.ini, a scary little text file that nevertheless is pretty important to know about if you fix computers. Microsoft changed how the boot menu works in Windows Vista and 7, helpfully removing the Edit button as you can see in the screenshots above.

You’re meant to use the even scarier command-line-only tool bcdedit, but I can’t be bothered learning how that works just to fix the incredibly basic problems I usually see (duplicate entries due to messed-up OS installs or repairs, or tweaking dualboot systems properly).

I’d like to share a lazier solution: VistaBootPRO gives you a perfectly good GUI for boot menu editing. The personal edition sells for US$10 on their site, but there appears to be a free version available here if you’re only going to need it once or twice.

VistaBootPRO on Windows 7.

It gives me a slightly scary error message on startup about Vista not being detected (I’m running Windows 7) and that I may “experience minor problems”, but it’s worked fine for the basic things I’ve done with it. YMMV.

Solved: Error 0×800704dd running Windows Update

Saturday, August 22nd, 2009

Frequently referenced as error 80240020. The fix depends on what version of Windows you use. Microsoft happily document each solution on its knowledgebase page here: http://support.microsoft.com/kb/910341/en-us

I wouldn’t bother blogging this, but the fix for Windows 2000, XP and 2003 involves adding a registry key that’s gone missing. Something happens to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\SensLogn, namely that it disappears. Not sure what’s causing it, but I’ve seen it on two PCs at work in the last week, and I quickly tired of re-typing the key information (there’s 14 different fields to fill in…).

Here for your (and my!) quick reference is SensLogn.reg. Right-click, save to anywhere, and merge with your registry on 2000, XP or 2003 to fix error 800704dd.

Solved: Blinking cursor, no boot on Toshiba Tecra M2

Thursday, August 6th, 2009

Here’s a weird one. Today it was a Tecra M2; I suspect it’d apply to a number of models, and in fact a number of different brands too.

This laptop had stopped booting off its hard drive. All it would do – after running through its boot device priority list including CD/FD/network boot – would sit there doing nothing but blinking a text cursor at me from the top left corner of the screen. No error message, nothing to indicate any kind of progress or failure, it’d just get to the point where it should be booting off the hard drive and did nothing.

We tested the RAM – no faults. We chkdsk /r’d the drive – no faults. We ran a different surface scan tool, no faults. I pulled the drive out and checked it on another machine – every file present and accounted for. There was nothing visibly wrong with the thing.

Google results were mostly unhelpful. Apparently you get this if you flash a Toshiba laptop with the wrong restore image. Plenty of people were directed to change the drive, or reinstall Windows, or a million other things that wouldn’t end up helping.

The actual problem is that certain laptops can’t boot off a partition that’s above a certain size. Older laptops won’t see drives above a certain size – Dell Inspiron 6000s came with a 100gb drive for a good reason – but if you have a boot partition above about 128gb, some Toshibas will silently fail to boot at all.

The clue came from this Tomshardware thread, where a guy with a Dell came in on a Toshiba discussion with the ultimate solution. I resized the partition from 160gb (the size of the drive) to 120gb (a size suitably under the 137gb that guy suggests – I initially tried ~135gb but that made no difference), put the drive back in the laptop, and voila. The XP boot logo never looked so sweet.

Worked for his Inspiron 9300, worked for my Tecra M2. Grab a copy of Partition Magic from somewhere and give it a go, you might be surprised.

Solved: Graphics flicker on GA-MA78GM-US2H

Thursday, June 25th, 2009

Gigabyte MA78GM-US2H motherboard box.

We just got two of these in at work today, and both went into new PCs. Both had the same graphics glitch: Some violent-looking video flicker the whole way through Windows XP setup, which calmed down a bit once the drivers were installed but then had a weird row of green boxes flickering across the top of the screen.

The guys in this forum thread suggested turning Cool’n'Quiet off in BIOS; that made no difference to me, but updating the BIOS fixed it for everyone. I went from version F2 to F5; it seems to be fixed in F3 and up. Go here and scroll down to get the latest BIOS update.

Our two boards were revision 1.0. There’s also apparently a v2.0 of this board with a slightly different chipset (SB710 instead of 700). I don’t know if it’s affected or not.

I’m surprised this made it through quality control; it’s an obvious problem and all you need to see it is to try installing XP. It happens on both CRT and LCD monitors. It’s easily fixed though – you just put the new BIOS image on a FAT32-formatted drive (a USB flash drive will do) and hit F8 from within BIOS to get to Q-Flash (or the End key from the POST screen).

Howto: Find drivers for XP on new laptops

Tuesday, June 23rd, 2009

This is increasingly becoming a common situation: You’ve got a brand new laptop, it’s got Vista, it runs like a dog, and you want XP on it instead. You’ve got a spare copy of XP – for one reason or another – and you’d like to install it.

Here’s the catch: Tons of new hardware is being brought out without drivers being written for Windows XP, and laptops are just full of it.

Case in point: an HP dv6836TX, which a customer recently brought in to have XP loaded on it. HP do not provide XP drivers for all of its hardware, only some of it, and it took me a good half a day to find everything. Software for the card reader – a Ricoh R5C822  – came from a similarly-specced Dell Inspiron 1525. The onboard LAN pretended to be a Realtek 8139, which XP has drivers for, but those drivers actually hung the system; it’s actually an RTL8102E, or something like that.

The simplest way to identify hardware in a computer is to run a program that looks at all the individual devices, matches them up to a big list of vendor and device IDs, and tells you who made each thing and roughly what it’s supposed to do. 99% of the time at work, we use Everest for that, which isn’t a free program but the trial version is perfectly capable of IDing hardware.

The graphics gave me the biggest headache by a long shot. NVidia do host drivers for laptop chipsets now, but because HP (and practically every other laptop maker…) subtlely customise their hardware, NV’s software for the 8400M GS failed to see any compatible hardware, and flat refused to install.

It’s the most frustrating kind of incompatibility: it comes down to one little text file missing one little line with some numbers in it, the result of which is that you’re completely dependent on your computer manufacturer for software updates.

Or, to put it another way: You’re not. I mention laptopvideo2go.com in passing on my driver guide, but today they deserve some serious recognition. These guys collect those little lines from all the laptops they and their friends can find, and put them all in one big text file – the .inf file, which lists all the hardware a driver is compatible with – so that NVidia’s own drivers will recognise NVidia’s own hardware.

It’s a bit tricky to do – their site is a little confusing in places, and financially supported by well-placed driver-promising ads where necessary – but their forum is run by human beings, and anybody even slightly technically minded ought to be able to figure it out.

I managed to, and that 6836TX went home running XP like a champ.

My latest venture

Saturday, June 6th, 2009

I have started a new project, in the same vein as my driver guide. I’m collecting service manuals of every laptop computer I can find and hosting them on a new page here: http://www.tim.id.au/blog/tims-laptop-service-manuals/

These files contain parts lists for each model, and how to disassemble them, down to the LCD screen and the motherboard. As a repair aid, they are invaluable, as they can easily halve the time it takes to replace a keyboard, and attempting a motherboard swap without one is a risky, unreliable procedure.

The manuals are often difficult to find, though; very few manufacturers actually publish them for the general public, and I strongly applaud and recommend those that do. Those that don’t, on the other hand, only make it more difficult to repair their laptop computers, which reflects badly on them as companies who care more about their sales than their support.

I invite everybody to have a look, email people the link, digg it, tweet it, whatever. The more people who see it and know it exists, the more will (hopefully) help me expand and improve it over time.

MMS/PXT on Exetel with Vodafone

Saturday, June 6th, 2009

This has been bugging me forever. I pay Exetel for my mobile service, and have never managed to get MMSes to work. Sending or receiving.

Vodafone (who Exetel resell) have a page that sends their MMS/GPRS/etc settings to your phone. I’d tried this a few times, and while the settings for net browsing worked fine, nothing I did ever made MMS work.

I finally got around to looking for a solid fix for this, and found a post on Exetel’s forums suggesting I go to my phone manufacturer’s support site, and get them to send me MMS settings.

I have no idea why this should work – Sony-Ericsson are many many steps more removed from my problem than Vodafone is – but it did work. Apparently S-E’s Vodafone settings work, while Vodafone’s Vodafone settings don’t.

Go on, try it. It worked for my K850i, it worked for that guy’s Motorola.

You think BIOS beep codes are hell? Try understanding the incomprehensibly wide array of settings required to make a mobile phone talk properly to its network. I hate phones.

That little orange light

Saturday, June 6th, 2009

A frequent question at work is whether or not you should turn your computer off at night. The answer is pretty simple: leave it on if you’re coming back to do something later, and leave it off overnight unless you’re downloading something.

(The above situations are kind of perpetual to most geeks, and answer 1B is often “get a second, low power, quiet computer to do your nightly torrenting for you while the firebreathing tiny god sleeps”.)

Not many people realise that their monitors also drain lots of power – large LCDs are often no better than the CRTs we used to lug around – and they still chew current in standby mode. One recent customer, though, was more worried about something… else.

Customer: Should I turn my monitor off at night? Does it do any damage leaving it on?
Coworker: It’ll still use a bit of power in standby mode, but it won’t damage anything to leave it on, no.
Customer: Oh… won’t that little orange light wear out though?
Coworker: *blink*