I think that DarkHououmon is right, did you run a virus scan on it? My old computer did something like that once, when I scanned it, I had a trojan or two on it. If that doesn't work, you'll have to take it to a computer shop, and you may have to have the Windows re-installed. I use Vista now, and I don't have any trouble with it.
Safe Mode doesn't work either? That's strange. My old computer always worked in safe mode, it was slow, but it always work. You may just want to take if to a computer shop if you can. You'll have to have everything take off your computer most likely, but it will work right again. When my computer gets gutted, it works fine for a long it. Any viruses, or programs or downloads that may have a virus will be removed too, and see if you can have Windows Defender or Norton Antivirus installed. I used Norton on my old computer, I rarely had any viruses, and with my new computer, I haven't had any yet (with Windows Defender).