I'm at my wits end here trying to figure out why this system is crashing. I'm using the fully updated Windows 7 Pro and the for some reason In have programs that are using 40-50% of the cpu just prior to a system crash. IDvault was the first progam to do this so I went into safe mode and removed the related Norton program. Then Google Chrome did the same thing so I removed it. Now Steam is doing the same thing. After each removal the system works fine for a short period of time. Without removal it simply crashed without any error message. After the last crash the sytem diagnostic in safe mode found that 'superfetch' was not running. After a reboot to regular windows the system worked again. I have not been able to reload Norton the program will download but not run.
I have run Windows Defender and Microsoft Safety Scanner but they have not located any virus and the system just crashed again but this time without any associated high cpu usage.
Thank you for the respones. I ran a number of scans that all came back negative for malware. Then I ran Killdisk and reloaded Windows as well as all the hardware and software updates. On the clean install the system ran fine for nearly a day but just crashed again with youtube up. The screen went black and froze with some wonderful rainbow effects...On the reboot it seems to be working fine with no unusual CPU usage but I expect it to crash again.