Hi Cyberdiva, I think hard drive powerwash fixed that problems with MOzilla browser, myself I tried this soft and  for unknown reason cleaned some junk files that were preventing me to instal a soft. Well now I found a giveaway of Hard Drive Powerwash
http://www.techishare.com/blog/tech/clean-windows-with-hard-drive-powerwash-giveaway/

And yes NirSoft are generous for offering some interesting soft to us as freewares. Regscanner is nice but I use RTSCANTool and the reason is that I earlier uninstalled Regscanner and didnt put it back. But I am surprised that after uninstalling sodt with Revo and cleaning registry with some tools RTSCANTOOL finds left over reg keys!!!!

Well possible your drive is corrupted so basically windows will popup with that message. Try to instal UNKNOWN DEVICES (http://www.zhangduo.com/udi.html) and see what will come up