Trying to fix a virus ridden computer. Can't install or download any AV software. Got hold of a kaspersky rescue disk.

Popped it on a USB drive. But there's no BIOS option to get a boot menu.

Motherboard is an MSI PM8PM-V. Any ideas?

I've unplugged the hard drive and the rescue disk doesn't seem to have worked anyway. Any ideas?

Can you use F10 or F12 to get to a boot menu selector?

Neither work, been across the F keys. The manual says F8. I've managed to get Avast installed and it's finding all sorts of shit. Just odd that I don't have the F8 option. Nothing shows on the POST screen. There was an option in the BIOS to enable booting of other devices, that was off, but even when changed to on it didn't change anything.

Have you tried running the ultimate boot cd? S'good for diagnosing problems and contains a lot of start up/boot management tools.
      

Right, best free Anti Virus please? I've scanned it with Avast and it found ~2500 infected files. "Repaired" those. Rebooted, running another scan because it keeps popping up about a malicious url being blocked. And there is an exe file that gets created in LocalSettings Temp folder that Avast deletes then it gets recreated every so often. It seems a root kit was found and some trojans. Booting into safe mode wasn't working before, but I'll give it another go. Any ideas on how to get rid apart from wiping the machine?

sometimes BIOS access is the DEL key (and occasionally ESC)

BIOS access is fine. It's access to the BIOS boot menu to select boot from USB etc.

oh right, I don't think I've ever known that to be a problem once you're in

Probably not explained myself correctly. When you boot there's often a message on the POST screen to press something like F8/F10/F12 which brings up a screen with a list of bootable devices. It's this message and option which seems to be missing.

I've recently stopped using MSSE and started using Bit Defender (Free). Supposed to be one of the best you can get and it's very light.

Go into BIOS and change boot order.

I'll give that a go. Currently doing a startup scan with Avast. I feel like I'm going to kill the computer removing all these infected files that can't be repaired.

Tried that, didn't seem to work for some reason, the USB drive wasn't an option. I tried with "bootable addon cards" first.

Think that was for Kosser.

Probably was. My quick reply box doesn't seem to be working today. Better clear my cache.

Found another boot disk image from a Mr. Hiren - with rootkit killers and AV on. However there doesn't seem to be anywhere to download it on their site. :C

Here's an alternative download.

Edit - 'Course this is assuming you've got an optical drive in the machine and it's setup to boot from it somewhere in the boot order before the hard drive.

Can you F8 to boot to a command prompt and then do format c:? that'd get rid of it!

(or from a Windows CD, as I imagine you probably can't format the drive the OS is running from.)

I've generally found a clean reinstall is faster, easier and more reliable than trying to av through it. The severity of the issue suggests it may have been root kitted.

I wanted to avoid that due to some software we probably don't have media for but I think tomorrow I'm going to wipe it and start from a clean install. My preferred option every time.