Computer will not boot

[Quarterdime]

Hello everyone. I'm currently posting this on my fathers PC.

Whenever I start my computer nothing on my monitor appears and no lights show on my keyboard. The last time my computer worked correctly was last night. I was downloading something on bittorent when a message appeared saying the operation could not be completed due to an I/O error. I ignored it and force started the torrent and then the message appeared again, this time bittorent started to hang. I tried to shut down all other applications but my computer froze and then had a blue screen.

I restarted the computer, everything booted up normally but took an abnormally long time to load. When it finally did load I decided to shut it down, which also took a long time. After this I waited a bit then tried to turn my computer back on but nothing on my monitor appeared and no l ights on my keyboard turned on. My mouse stayed on perpetually in the sense that even when I turned my computer off if I had the power cord plugged into it the mouse would always have the light on. When my computer turns on everything seems normal, its just that nothing appears on the monitor, and i've tried multiple monitors.


Intel® Pentium Dual-Core E5400 2.7GHz



Operating System

Windows 7 64 bit home premium

Memory

2 GB PC5400 DDR2



Graphics Card

NVIDIA® GeForce® GTS 450


Hard Drive

3.5” SATA 500 GB (7200 rpm)



Optical Drive

DVD R/RW



Power Supply

500 Watts



Networking

Integrated 10/100 Ethernet, No wireless LAN


Chassis

CoolerMaster Elite 334 NVIDIA Edition



Front Productivity Ports

2 USB, 1 Mic, 1 Audio



Back Ports

1 Serial port
1 VGA port
1 LAN
4 USB 2.0 Ports
3/6 Flex Audio Jacks
1 PS/2 mouse port
1 PS/2 keyboard port



Audio

Integrated 7.1 channel sound with front audio ports



The last hardware change was months ago when I switched my gt 9800 with a gtx 450. Everything has been wokring fine more or less since then.

Here are the steps I've taken to try and fi this myself. I actually think I did more damage than good, because when I first started to fiddle with my computer inside I didn't touch the power supply so I think I might have short circuited something in my computer.

1. Take both ram out and try to start it then.
2. Switch out my video card with my previous one ot no avail.
3. Hook up my computer tp another monitor and see if that worked.

I really hope someone can help me. This computer is my life. Its my only link ot the outside world and if my computer breaks that link is severed.

 

[popatim]

have you measured the voltages on the power supply?

 

[Quarterdime]

No because I've never had a need to in the two years I've had the computer and I also don't know how to do so.

 

[Quarterdime]

Well I don't think I'll get an answer so I'll just go on a limb and say my motherboard is fried and I'll just replace that and see what happens.