Guys i need your help my computer always hang and unreponsive.?

even i'm in a middle of something like surfing the net or openning a program it suddenly hang and sometimes its just black screen like shutdowning but you have to push the reboot botton to restart the computer. and it happens anytime. i don't know what was happening with my computer and i also scanned it with my antivirus and all viruses are gone..guys i need your help to fix it and to find out what's wrong. please please help. thanks

Guys i need your help my computer always hang and unreponsive.?computer security

Sounds like a hardware problem. Here's the list of things to check.

Monitor temperatures to make sure it's not over heating.

Check to make sure all components are seated properly.

RAM

Graphics card

Other expansion cards

Power Supply

and finally MoBo / Processor

Guys i need your help my computer always hang and unreponsive.?free spyware remobal

I would start with looking inside the computer for an accumulation of dust that can cause overheating. Make sure everything is clean inside - use a can of dust off or even a portable vacuum.

You stated you scanned for viruses - but how about Spyware/Adware? Download Super Anti-Spyware (free download) and scan throughly.
Plan A: Go to the Control Panel, then click on power options and look for any timed options. could just be your lousy screensaver.