System wont boot

[Vickram Kapoor]

My old hard disk wasnt booting so I tried reinstalling the os win 7 which didnt go past the startup screen.

then I bought a new hard disk and the same system arises when I try to load win 7

the screen shows windows loading files but the bar is complete the screen goes black and nothing happens

please could someone help me out here

 

[deanlaing12]

Does the hard drive come with both molex and sata power connections?If so, make sure it is set to use the correct one in the bios. Sometimes the motherboard will run with whatever it plugged in, but optimizing the settings keeps it reliably stable.

Look into http://www.memtest.org/

Run this program, in my experiences, the problem you are describing can sometimes occur from the ram being corrupt. (Do at least 5 checks in my opinion, I think 7 is overkill but whatever, it is an overnight job anyhow) Also, it might be worth doing it with 1 stick of ram at a time, it is less confusing that way.
If you get errors, replace the ram.

When I got my £2,000 laptop, (Acer by the way), one of the sticks of ram broke after about 2 months.

Try using a different connector for the monitor temporarily. (rule out the easy stuff)