Windows 7 - Computer having trouble starting up

This is a hardware problem with the computer than a problem with Windows 7. I think that it may have bad caps but I've been proven wrong before. What happens is once the power button is pressed the fan goes at full power and nothing else happens. Also if it is something big wrong with it (Mobo, CPU) can you tell me what parts are still useable because I am thinking of buying or building a computer. This isn't my primary computer so if you need the specs I'll try my best to retrieve them

Here's a video of what happens:


Pictures of the inside are attached

If you need more just ask

Pictures were not attached for some reason

Can you boot into the BIOS?

Check all connections to make sure that they are connected.

If you can not boot into the bios, replace the power supply unit.

The weird thing is that it's really picky.. Sometimes it boots into the BIOS and sometimes it doesn't. When it does get past the BIOS it just freezes while loading up Windows

Help me out here. In your system specs it says Compaq.

could you please add the model and whether it's a laptop or desktop.

This is a tricky problem because of the intermittent nature.
I would assume for the moment that as it sometimes manages to get past the BIOS screen that the hardware CPU, RAM, and Graphic chip are ok.
I would also assume for the moment that Windows not starting is a seperate problem.
Does your monitor switch on properly? it may be wise to check it using another monitor and cable? that at least should be easy for you to check.
I also suggest starting the PC with the side off so that you can check the operation of both the CPU and PSU fans.
I then think you need to check all cable connections by physically removing and replacing the cables. If you still have no joy you will then need to check the seating of all hardware in the same way.
Finally the only option left is to try replacing parts one at a time I imagine this may prove difficult due to the age of the PC and I would, if I was you consider if it is worth the effort.