Goes beyond me. I'm a pretty radical person, and my experience is that a total re-installation of Windows is quite often less time consuming than trying to desperately find a fix. This present problem has been battled for a week, and no obvious solution seems to be at hand. There's just something "wrong"... it could be a vicious virus or other attack, dunno. Or merely a corrupted Windows installation, that happens too.
If your computer has warranty left, you might try that. People in customer service / sales are usually quite helpful.
Otherwise, I would suggest that you install Windows from a clear base:
1. Safe copy your personal files to another hard disk or a DVD or something. Since there is a risk of malware, it could be wise to do it in .zip or other packed format. Antivirus programs can usually scan packed formats, but viruses et.al. cannot perform from there. Thus, you have the possibility to scan it all, before unpacking it - so you won't contaminate your new installation.
2. Use e.g. AOMEI
http://www.aomeitech.com/aomei-partition-assistant.html to first delete your disk's partition(s), this will clear the disk to its factory form. Then re-partition the disk, NTFS format. This will all happen via BIOS, you may need to change boot order. Commands here vary with computer motherboard. I would recommend to have the disc, be it AOMEI or other, burned by another computer, a friend's or something, known to be clean.
3. I recommend you create at least two partitions: one where you have Windows plus programs, should be 50Gb or upwards, depending on how much stuff you have there, besides Windows. Another partition where you have your personal files. Preferably, you could have two separate physical disks. Either way, you can re-install Windows anytime, not having your personal files affected, since they are separated.
4. Install Windows in the smaller (?) partition = would be C. And to be on the safe side, have your major CD / DVD / Blue Ray station named D --- many games get a hiccups if they aren't in D.
Best of all.
