I have a new problem with my computer:
Dell Inspiron 3847 Desktop
Windows 7 Home Premium
System freezes after about 15 or 20 minutes of idling (inactivity). Do not get a BSOD. Computer does not reboot itself. It just freezes up with whatever is on the screen. It does not matter if I have a screen saver active or not. The mouse cursor will not move at all, or will move just a tad bid until the spinning circle icon shows up and then its stuck there. Only way to recover from this is to pull the power cord for a minute and start over.
Sometimes I'll eventually get a pop-up warning saying "Warning - Unresponsive Script - not responding" or something similar. Most times I don't get any such warning.
Most of the time I walk off for a while FireFox is running. I suspected that FireFox was the problem so I have purposely closed FireFox before letting the system idle for a while. Makes no difference, system still freezes after 15 or 20 minutes. (FireFox is updated to the latest version.)
I have tried to run a full system scan with McAfee AntiVirus, but it takes too long to run. Scan gets to about 40% and then the 15 or 20 minutes is up and the system freezes so the scan never finishes. A quick-scan with McAfee AntiVirus worked and reported no issues. I was also able to run a scan with MalwareBytes Anti-Malware (free version). That scan reported no issues. Also ran MalwareBytes Anti-Rootkit. That found no issues either.
Any advice on what to look for or what to try next would be appreciated.