Could be malware related or possibly a hardware issue. Have you noticed the computer running a bit hot lately, is there hot air coming out of the fan in the rear of the computer ?
Download DDS from one of the links below, save it to your desktop.
Link 1 Link 2
Double click the tool to run it.
A black Screen will open, just read the contents and do nothing.
When the tool finishes, it will open 2 reports, DDS.txt and attach.txt
Copy/Paste the contents of 'DDS.txt' into your post.
'attach.txt' should be zipped using Windows native zip utility and attached to your post. Compress and uncompress files (zip files)