if i was going over your computer, I'd do the following steps,
1 - http://www.piriform.com/ccleaner ccleaner cleans out your temp files, as well as your registry, these may have funky files ....or you 'may' have malware in your system ? ( or possibly failing components , but first check the least expensive route with these tools )
2 - http://www.malwarebytes.org/ scan your system for possible malware
3 - http://www.revouninstaller.com/ they have a free uninstaller, that cleans out better than the stock windows uninstallers, this helps with programs that may be interfering with your normal system function. a corrupt file loaded to memory can cause trouble.
4 - Update your adobe flash software, www.adobe.com
5 - Make sure you have the latest Java version, www.java.com ( open the control panel click Java, click advanced settings, then under "Temporary internet Files" select "settings" then "delete temporary internet files" this will also clear any potential mal functioning java files.
6 - make sure your os is up to date.
7 -If after this you do not see an improvement, you have to start doing testing for any failing components, such as video cards, ram card, hard drive / bad sectors, mother board as mentioned in another post - which a failing bios battery will change / reset the date - usually to the past when it was first created , not the future.
I hope this helps, you have to set a path to troubleshoot effectively ....start with software , after you go down the checklist, then start with hardware.
- one more -
Dust can become a conductor and cause shorts in your computer, if by chance your computer hasn't been opened in a long time, it may be advisable to get a can of compressed air and possibly a vacuum cleaner fitted with a small / appropriate hose if there is are dust bunnies! Be sure to unplug your computer and wait at least 10 minutes for the power supply to lose any charge before you begin to clean, also make sure you are static free, touch something metal ...as static kills computers too. Dust is a major killer of otherwise functional computers, it kills the ventilation and causes shorts...there is a chance, all be it small, that your system may be shorting from dust build up as well. computer components fail and overheat from lack of ventilation as well. Again, it's not likelly, but a dusty motherboard can cause errors as you have mentioned , as well as failing drives.
Good luck.
☯🐉
"To define Tao is to defile it" - Lao Tzu