I have been using Avast Home for about a year now and have been very happy with it's performance. (I had been using Norton SystemWorks 2003 previously). A few days ago, I tried re-installing SystemWorks (minus the AV) so I could use some of the other utilities such as Disk Doctor, etc. When I ran DD, it completely froze up my computer. I never even tried any other features and removed SystemWorks using Norton's own application remover and then double checking with Windows add/remove programs. Having had problems in the past with Norton not being completely removed, I also ran a program called symcln.exe that I had downloaded from a friend which removed some registry entries that Norton leaves behind (which prevents their own programs from being reloaded weirdly enough). Anyway, now, when I run the Avast on-access scanner it rapidly consumes all of my CPU cycles, making all other running applications act as if they are not responding (they are but just very slowly, it takes up to 1/2 hour or more to change folders in explorer for instance). It also caused Windows Explorer to terminate due to it's accessing illegal memory locations. I'm using a computer with an athlon 64-55fx processor and 1 GB of memory. What must I do to fix this problem?