Win7 freezing - taskbar animations / mouse working, but nothing else

I'm being driven mad by this problem and hope it might be able to help others, too, as I've seen similar threads but nothing quite like this issue.

Windows loads OK but after a while (either leaving it idle, or doing something low-demand like scrolling a web page or working in any other program) the program I'm in freezes and goes whitish. The cursor changes to the spinning circle. Usually I can alt+tab to other things, which are also all frozen. I can alt+tab back to the desktop, where the mouse is the normal cursor, and the taskbar still animates when I mouseover it, and I can type something into the search bar (like "event viewer" for example) but it doesn't do anything else apart from showing me the text I've typed - if I click on anything in the taskbar or the start menu, or on the desktop icons, nothing appears to happen.

The only way to get out of the PC is to do a hard reset with the power button, and there is no evidence in the event viewer of anything apart from a note that windows was exited without shutting down correctly.

I've tried everything I can think of but I still get the same problem. So I've updated motherboard BIOS, updated all the drivers including motherboard drivers, updated graphics drivers, removed all hard drives except the system one, uninstalled Comodo Internet security, uninstalled Firefox etc etc. I've run sfc/ scannow which says there are no system files missing. The performance monitor doesn't indicate anything untoward and I've got windows managing my paging file on the system drive. This issue even happened in Safe Mode with Networking.

I've also run several malware / virus checks: Spybot Search and Destroy, Malwarebytes Anti-Malware, Comodo's own scan, Ccleaner, Glary Utilities. The system appears clean.

I've spent hours and hours trying different things and I hope there's someone that can suggest something to try before I go crazy with lack of sleep!!

If I need to post something about what's running / about my system, please let me know and I'll post it.

Cheers - here's hoping for someone who can help.

Mark try these



https://www.sevenforums.com/tutorials/433-disk-check.html < DO NOT run on a SSD

http://www.superantispyware.com/


http://www.bleepingcomputer.com/download/adwcleaner/

download from bleeping computer
then Free Malware Removal Tools scroll down to the TDSSKiller and run it delete any rubbish you find.

Aha - so I've been managing to get it to run for nearly 45 minutes while I created a web page for my school choir, uploaded it and some files, and ran filezilla to change some directories, also adding a password to an online folder via firefox. All working flawlessly, and I was checking the music I'd uploaded online.

After about a few minutes of listening to this (while tidying up and saving my web design in Webplus), I opened windows explorer to search for a folder, and the machine whited out and did its spinning circle of death thing. The search results didn't appear instantly like they normally do and I got an empty folder with the green bar moving slowly from left to right along the top. It didn't do anything else. However, the music (playing online via firefox / quicktime plugin 7.7.4) was still playing fine, and ran all the way to the end.

Nothing else happened in windows explorer and none of my open programs would respond. Eventually I had to interrupt the power as usual to get out of the pc. But hopefully there's a clue there for someone. Windows search has been troublesome and sometimes the indexing doesn't work so it runs really slowly. In the past it has reported corrupted files in Event Viewer (but that could have been happening a lot and I just never looked before).

I have had a good look at event viewer up to the time of this latest hang and can find nothing which seems to be related to windows search or anything else that could indicate a cause. But please anyone come back with suggestions for anything to look for as I have to start a big video editing project for a client and I'm really nervous about losing time / work.