Comments: I tried this for someone's notebook recently and had to make some modifications. The instructions above would not make a working bootable USB for me. Grab the Kaspersky ISO from the above link. Then go to Pendrivelinux.com and grab Multiboot USB. It worked perfectly.
You can also later add ISO's to the USB boot menu (Ubuntu 10.10 for example). It can even download the ISO and install. You choose what to install from a menu. I mentioned Ubuntu and that may seem overkill for troubleshooting but it is a no brain linux for accessing ntfs drives. I have been busy loading stuff on the flash drive. It works. I can't update the distros using ISO's so what you have is what you stay with.
Multiboot USB is an interesting and useful tool. Actually I am tempted to change the title of this post to Multiboot USB.
PS: I am working on how to update Kaspersky definitions http://agnipulse.com/2009/12/kaspersky-rescue-disk-updater/ The update is working. I should just be able to rename and copy the updated "rescue.iso" to the USB drive and have updated definitions. At least all the elements for this procedure are here somewhere.
If you are wondering what else to do with your USB dirve, look at LifeHacker's 10 things article.
Set up a Win7 install? Here is the link. (I trying to figure out how to get both 32 and 64 on the same thumb drive.) But a single works fine.
What if your BIOS will not boot from USB? Try this. (How much can I add to this post?)
