I've just decided to roll back a computer from Windows 10 to Windows 7. I have a clonezilla image of it in a clean working state from about 2 years ago. The only hardware changes during that time have been replacing the 3TB boot drive with a 6TB boot drive.
I restored the image. Expanded the partition to fill the available space. It boots, everything seems to be working fine but then...
Every now and then (at least once in 30 minutes use) I'll notice that its almost entirely unresponsive. At the point if I open 'My Computer' I can see that my C: is showing up without disk space information below it. If I wait about 5 minutes it will then show as about 90% (or some other random percentage) full. There's less than 20GB of disk space actually in use out of 6TB. Every time I refresh the page, the free space increases until eventually it gets back to normal. At this point the computer starts behaving normally again.
Things I've tried.
Memory and hard drive tests with every program/boot disk I can lay by hands on
Resetting all file and registry permissions.
Re-registering all system files
Setting all services back to default startup
Wiping the whole windows update catalogue and updating using WSUSOFFLINE (this is still running)
I've probably tried a whole lot more that I've forgotten at this point.
Any advice? If any further information is required please ask, cant really get anything until WSUSOFFLINE has eventually finished.