Did your hard drive all of the sudden no longer wants to boot up? If your drive is fairly old, it's quite possible that it has lost it's luster to tolerate heat from the use of it. Let me quote the following:
One of the scariest things you'll ever hear is the telltale whirring and clicking of a cratered hard drive. Your system won't boot, all your documents are gone, and never again will you see all those pictures you downloaded, it's time to throw the Hail Mary and clear some room in the freezer.
Like all electronics and mechanical gear, hard drives are susceptible to overheating. The components grow weaker and weaker, becoming more heat-sensitive. When they get to the point of no return, what normally would have been a regular operating temperature may no longer be tolerable. Time to chill out.
Pop the top on your computer and find the hard drive. Unplug the wide data cable and the smaller power connector. Remove any screws holding the drive in the computer and slide it out. Did I forget to mention that you should not only turn the computer off but unplug it, as well? And that you should wait a minute for any remaining juice in the motherboard's components to drain away? Or that you should wear one of those grounding-strap things on your wrist and clip the other end to the chassis? Oops. I never remember to tell you those things. Hope you didn't kill your computer already.
Now rummage through the cupboard for a couple of Ziploc bags. The quart size will probably work for most drives. Double-bag the drive before you stick it in the freezer. Hard drives react badly to wet stuff, you know, plus this method will reduce condensation when you pull it out and try to fire it up again.
Tuck your drive somewhere between the Nutter Butters and the Tupperware full of unidentifiable stuff and leave it for at least eight hours. Don't forget about it, though. You don't want your wife slipping it into the microwave by mistake when she makes her midnight Lean Cuisine run. That wouldn't make anybody happy.
In the cart-before-the-horse department, you should already have had your old drive replaced (or done it yourself), and Windows should be up and running, because next you're going to pull that drive-sicle out and install it as a secondary drive.
Look, there's every chance that the old drive could fire up like everything was normal after you simply put it back in place. But it went bad once, and it will go bad again. This freezer deal is a temporary fix. If you can install it as a secondary, there's a pretty good chance it'll come up long enough to copy your data files to the new drive. Don't try to copy program files, though. You're just going to have to reinstall those on the new drive.