No Signal detected

[Xoul]

I am getting this error more and more often,usually when I plug in anything into usb ports,the screen goes black and NO SIGNAL DETECTED is shown on screen.
Sometimes when I just start the pc this happens after windows loading screen,and by hearing the sound of windows loading I can say that the windows loaded fine only display is not shown.
Also happens when
-switching tabs while playing a game
-when plugging in speakers
-when I disable my network adapter

This error is really annoying and bugging me,I have to restart my pc directly whenever this shows up,and I often lose my work because of that.

Please help,my pc specs:
Dual Core E5200 @ 2.50 Ghz
160gb IDE hdd
Nvidia 8600 GTS
2 GB CORSAIR DHX DDR2
Windows 7 Ultimate Edition (32 Bit)

 

[Harvey]

You didn't identify your motherboard. Have you checked for any BIOS updates with the maker?

Try searching Google for your motherboard model and search terms like "USB," "problem," "no signal," etc.

Good luck.

 

[Xoul]

I have dg31pr Intel board,with latest bios update.
I have searched hours on google but no luck
I tried removing my video card and now computer works fine no error,could it be the video card ?

 

[TeeJay1952]

Does vid card have power connectors?
What is rating on your Power Supply? (new cards exceeds)

 

[Xoul]

Yes the video card has power connector,my power supply is 460 watts,Its coolermaster power supply I just bought it in early 2010.

EDIT: Now I don't think its the video card as I continued using my computer without video card,I could hear the same unplugging/plugging sound at some times,and see the screen flashing(like it does before no signal detected),although I didn't get no signal detected but there were signs that could tell me that its not the video card... I am totally confused now....

EDIT: Its confirmed,its not video card,I got the no signal detected even without the video card