How do I get isass.exe virus off my computer at home that won't boot up operating sys is xphome edition virus was determined by dell case#144804999 just need to know how to get off a puter that won't boot up
Heard can do this with xp disc not the restore one, also heard can go into the clock and set it so can get inthere and get the virus out please help

OK start at the beginning and we maybe able to help you more.
A few things we need to know are:

Operating system
Why you think you have this virus
Why it isn't booting
What you have tried
ANY error messages
Anything else that has happened to your computer recently, however small

There a ton of information on the net about this issue, loads right HERE (http://www.google.com/search?lr=&ie=UTF-8&oe=UTF-8&q=isass.exe)

Thank you

Thanks for updating your post after I had posted my answer ;)

Now if your machine is truly that infected then your best course of action would be to use the Dell restore disc and completely wipe it and start again from a fresh format.
It is possible to do a repair install with a "normal" XP cd, Here's (https://www.askmehelpdesk.com/operating-systems/cannot-acces-recovery-console-35285.html#post171255)instructions on how to do it.