A result of inadequate care of your computer.
1.Do you defrag your harddrive every month?
2.Do you run diskcleanup (CCleaner is a better altenrnative) every week?
3.Do you run Virus/Adware/Spyware scans every week or so?
4.Do you check the .exe files before opening them?
5.Do you overclock, if so, do you use good quality Thermal Paste? Also if you overclock at a very highlevel, do you have aftermarkest HS/F?
6.Do you use compress air/vaccum to clean the computer of dust?
If you don't do those then, well its already too late isn't it lol.
To fix overheating problems, clear the dust and apply Arctic Silver 5.
To clear your windows problem, scan for virus/adware/spyware. If it comes clean, run CCleaner(www.ccleaner.com
), do a disk defrag/scan. If all that doesn't help, installing windows again wouldnt be a bad idea.