Virus scan brings PC to it's knees

I have a triple boot system two XPPro sp3 setups and Win7 64 bit.

I have only installed CIS 6 on two of my drives.

First instalment of CIS is on XPPro over the top of an older version.

Second is Instalment of CIS is on Win7 and a clean instalment.

I have the same issue on both Operating systems and that is after 10 minutes of scanning it slows to a crawl and bring the PC down with it.
Example to shut down the scan after 20minutes takes around 3-4 minutes for the instructions to get processed.
This delay also happens when I try and open new apps or browse the Net.

After shutting down the scan the PC takes around a minute or so to return to normal.

I’ve tried messing with the priority but it makes no obvious difference and CPU seems to be only around 27% - 30%

System is i5 750 , 3.4 Ghz XPPRO/Win7 64Bit 16Gig memory.

I don’t want to have to revert to a previous version but 6 is really unusable right now.

Any help?

Cheers Sel.

Please make sure that there are no left overs of previously uninstalled security programs around. Not all uninstallers do a proper job. Left over applications, drivers or services can cause all sort of “interesting effects”.

Try using removal tools for those programs to remove them. Here is a list of removal tools for common av programs: ESET Knowledgebase .