Hi, I’ve just tried Repair of my AVAST Internet Security prog in Add/Remove software in my Windows XP. Tried doing a Quick Scan and it crashed my computer again. Before it did it on the Full Scan. Definitely something to do with the scan trying to scan SVC files, which I think are Microsoft’s files. It looks like they’re stopping the scan at a certain point and actually succeeding in crashing the whole program. Prior to this, these SVC files never appeared on the scans so why are they there now? :-\
Crash or freeze?
If I’m not mistaken all “svc” files have an “exe” extension. Therefore they should be scanned.
Try a repair from safe mode. 
Para-Noid,thanks for information.
I didn’t know that is possible to do repair from safe mode.
I don’t need to do repair Avast,but it is good to know.