System is Win 7 Home Premium on Dell XPS 8100.
This problem happened about a year ago and a reformat fixed it until now. At some indeterminate time of using my system it will completely slow down. Web pages wont' load, CTRL+ALT+DEL takes a minute or more to bring up the menu. Selecting Task Manager may take another couple minutes to come up.
All the while that this is happening there is a rhythmic and regular hard drive access sound. It's a short 1/2 second hard drive sound, then 2 seconds of nothing, then 1/2 second of hard drive sound, then nothing.
When Task Manager does finally start nothing of interest or unusual shows up in the process list. Malware Bytes says the system is clean. When I reboot (usually having to pull the power plug) it'll run fine again for several days so I don't think it's a physical drive problem (and it passes the manufacturer drive check utility).
I've never been able to get resource monitor to load so while this is happening, so I'm going to just leave it open on a different monitor to try and see what process might be hitting the drive and causing the system to slow down.