However in the case of switching to new hardware you want to make sure the vendor provides drivers for Windows 7. They don't all do that.
Another option is give up on the old drive and your nice Windows 7 that you are used to. Plug the old drive into the new computer with an external connector (USB to SATA connector, e.g. Walmart link That will make you old drive an external drive on the new computer and you can find and reuse your files. But you will have to recreate your whole working environment (buy the applications) on the new computer with its new disk and new OS.
You can also buy a small box with the SATA to USB and put your old drive in that box and use it as a permanent external drive.
You can also try to find an old used laptop with Windows 7 and recreate your working environment on there (probably have to buy Office and other apps). Then copy the files from the old drive into the new computer.
However, the first thing I would do in your case is pull the old drive from the old laptop, get the Walmart thing, plug that old drive into some friend's computer and look at it. Make sure it works, and try to find the files you want to save.
You can also use the adapter from post 45 instead of the one from Walmart.