Blinking White Cursor startup

Ok guys here is my dilemma, it's driving me nuts.
I'll start from the beginning
I was having problems with my status bar icons being blank even after a brand new installation and random crashing.
Then my video card failed and was giving the beep error for that.
Replaced the card
Cannot install windows onto hard drive via the PC, the installation gets 90% through loading files and then comes up with an error.
Tried via disk and USB tried both windows 7 and windows 8 to no avail.
I installed windows via my laptop onto my hard drive via a dock using the program to load windows into an external hard drive, it worked and I thought my bad luck had ended.
I booted the hard drive on the laptop and it booted windows.
Now I think yay! Time to put it back into pc thinking the problems fixed.
I press the power button and go through the usual boot sequence until...it goes to the blinking white cursor.
I cannot get past this, have made the hard drive the primary one to be booted from in the bios and still no joy.
Which is why I've come to you guys to find out if anyone has had this problem and know how to fix this

Well can't wait to finally have this issue resolved *crosses fingers

You cannot expect Win7 to start up on different hardware with completely different drivers without first using a procedure to Adjust Win7 to boot on new hardware with Paragon Adaptive Restore CD. Then if it still fails to boot with all other HD's unplugged, confirm the Partition Marked Active is 100mb System Reserved (preferred if you have it) or C, then run Startup Repair - Run 3 Separate Times .

It would be better to find out why you can't install Win7. Work though the steps for Overcoming Windows 7 Installation Failures - Windows 7 Help Forums which resolve 90% of installation problems.

If you get an error again, then google the error text to find out others have worked around it. Post it back here as well since we may have seen it before.