My pc boots but nothing works

[iAlen]

So I went on vacation for 4 weeks after returning, I plugged my pc back in and try to start it. After booting it shows me ''Starting Windows'' and reboots so I tried starting safe mode but that showed me a black screen and did nothing. I also tried Reinstalling Windows but the same thing happens It loads the files and then black screen nothing works. So I decided to use another hard drive but it also didn't work the same thing happens.

My pc is an Alienware Aurora R2 with Windows 7 Home Premium 64 bit

Not really sure what my specs are but my videecard is an HD Radeon 5670
I have a seagate hd 500gb
My processor is an i3 not sure what sort but a dual core 3,02 Ghz
and I have 3gb ram the motherboard is made for Alienware not sure what it's called.

I'm really not sure what the problem is, could somebody help me ?

 

[gregrocker]

Work through these steps starting with the hardware tests for Troubleshooting Windows 7 Failure to Boot.

 

[ReviverSoft]

Silly question, but is there anyone else at home who could have used the computer?

Also, see if you can get your computer to boot off a Linux based LiveCD like Knoppix or Ubuntu. You will first need to access the BIOS and change the boot order to your CD drive. This should tell us if it a hardware problem.

Edit: Try gregrocker suggestion first