I've been running Boot Camp on my MacBook for ages but for some reason yesterday Windows decided that it didn't want to start up, leaving me stranded in the sleek and shiny but ultimately LotRO-less OS X.

 

A few days ago I got a surprise warning from Avira about some worm or other but it seemed to deal with it and the file was gone when I looked so I didn't bother investigating further. My question is: Is it possible to run a virus scan for Windows viruses from OS X? It seems like a good idea, since Windows isn't running no malware or anything can activate and they should be easy to remove, but I can't find anything about it on The Google.

ClamXav might work.

AVG do a Rescue CD / USB. F-Secure Rescue CD is another good one. Both are available as ISO images.

If it's Windows 7 or Vista, booting from the installation DVD will give you a few different repair options to try.

Oh and once you've got it working again, scrap Avira. Get Microsoft Security Essentials. Free and no nag screen.

I actually just got ClamXav, was about to post saying I might have fixed the issue already. :]

 

It's currently scanning my Windows partitions and has flagged up a few already so it's looking promising.

 

Is MSE that good? I use Avira on my laptop (clearly hasn't been that effective) and Avast on my desktop (fine so far).

I recently switched to it from NOD32!

It's as good as the other free ones, most importantly it's unobtrusive and also incredibly easy to use. Plus it scores extra points for not nagging you to upgrade to premium editions like Avira or Avast do, simply because there isn't one. The only oddity is that by default it doesn't scan USB drives, but you can switch that on in the settings if you want to.

Ok, the virus scan worked and all but XP still won't start up. I've tried booting in safe mode and last good configuration and every time it gets past the loading bar splash screen there's what looks like a split second of BSoD and it restarts. :/

 

Any ideas? Is there any kind of scandisk I can run from OS X, or some way to repair install windows without having the CD?

Do you have a pre-crashing registry backup?

Not unless Windows saves it automatically. :(

Unless you have/can borrow/jim an installer cd (to run the recovery console from), you are probably not going to be able to easily rescue it. At least you can still get the data off it.

Thanks for the heads up on MSE, have passed on the info.

(appled)

It may well do, depends if you actively turned off system restore, if not you may be able to recover to a system restore point. If you're running snow leopard or leopard then you can use the built in disk tools in OSX to scan an NTFS volume for file integrity if you install NTFS-3G first which allows you to do everything you could possibly need to with an NTFS partition in OSX (read/write instead of just read).

You have to be able to boot into windows to use system restore. It's never actually worked for me, even when I was able to boot up and try it. It can also really slow down your pc as it writes restore points at seemingly random intervals, and will do everything on your hdd (requiring vast amounts of storage), unless you deliberately exclude partitions.

 

I've had better luck using the backup utility, it will even restore from another installation, as long as you point it at the right partition(s). Furthermore you can select which individual files to restore, if you know exactly where the problem is. Best thing is to make a backup right after a clean install, again after installing drivers, and again after main apps (keeping each backup on optical media).

 

It is way faster than having to go back and do a clean install.

I'd try booting from an XP CD and running a repair installation of it. Ignore the recovery console bits and continue as if it were a fresh installation. At some point, it should scan for existing copies of Windows, spot the one that's there and give you a "repair" option for it. This should retain all programs and settings, but should overwrite all system files with clean copies in case one has become screwed up.

>Ignore the recovery console bits

You have nothing to lose by running the recovery option first. The problem is as likely to be a disk error as it is a corrupted system file, as far as we know at this point. Repairing an NTFS disk is only 100% bulletproof when done from Windows (as opposed to using OS X/Linux and NTFS 3G), and that is one of the main things recovery console does (the others are restore MBR and boot files).

Another disk repair option is to pull the drive, stick it in another pc, and repair it from there. You could even try manually restoring some known, critical system files, removing graphics drivers, anything that will get it to boot into safe mode.

If disk repair doesn't work, then try a repair installation -- then you will have to re-install all patches, and likely a fair bit of drivers and apps too.

And what commands would you run from the recovery console? As it boots, the MBR etc. is OK. Chkdsk is also unlikely to turn a none-booting Windows installation into a booting installation. It may fix a bad sector, but it won't recover the file which was sitting there. The recovery console is useful for specific tasks, but just "fixing a version of Windows which blue screens during the boot" isn't really one of them.

Suggesting that switching the drive into another machine and manually copying DLLs around is likely to be faster and less painful than a simple repair installation then a re-installation of a few patches though is just daft!

What Dave!! said basically. I've fixed so many XP installations with a Repair Installation.

 

In this case he might not have another PC to stick the drive into meaning that option wouldn't be possible.

>Chkdsk is also unlikely to turn a none-booting Windows installation into a booting installation. It may fix a bad sector, but it won't recover the file which was sitting there.

 

You've heard of journallng?

True. He might not.

OTOH, he has stated he does not have an installer cd...

I've fixed several unbootable Windows installations using both methods. If it works, the recovery console is way faster. If it doesn't, you can still do the other.

Of course the best way is to plan for inevitable Windows failure, and set up two Windows installations on the same pc, one for backup availability and recovery only.

I have no Windows CD available, but I do have another PC (although like I said, it's a MacBook and it's still under warranty so pulling out the drive isn't really an option) and full access to the borked HDD from OS X. I ran OS X's disk utility repair on the drive and it did something for a while but made no difference. :(

Are you able to download and burn an XP CD?