curveball323 :
We will need a lot more information than you provided to help you with your case. for example where does the computer fail to boot? does it fail before initializing the bios or does it fail upon accessing the Boot sequence of the HDD? it is a 500gb SSD or HDD? if you can't even get into the bios then your problem is most likely a hardware failure on the motherboard. if it does initialize the bios get into the bios and see if something messed up your boot sequence. Check to see if HDD boot is the main source for your OS boot and not the CD drive or USB. if all of that is correct and its still having problems go back into the bios and check to boot from CD instead of HDD and put your Windows 7 install disc into the tray. make sure the OS is even on the disc. you can't just put a new HDD into your computer and expect it to boot Windows with all your same stuff you had on your old Drive. when and if you do finally get it to boot correctly you can buy a SATA to USB connector and attach your old hard drive assuming its not fried to your computer and get your old stuff off of it. if you have a problem getting stuff off of it that you need there are many different companies that deal with data extraction from broken discs. they will be able to get anything you need off your old hard drive.
OK here is more details..
it does boot BIOS, once done, I used to get a hardware failure message but would still boot the hard drive. Its HDD, but truthfully it doesnt matter because I swapped it to see if the hard drive was the issue and its not. With the original hard drive, it would automatically go into startup recovery, and it would fail to find the issue, would reboot, and do the same. So, I tried option 2, to wipe the hard drive and reinstall windows. I put in XP, and it tells me it fails to detect a hard drive, to make sure its plugged in properly and so on...
so, I put in the second hard drive, attempted to install XP on it, and its doing the same thing.
Hope this helps!! and thanks for your help guys!