When you reinstall, more than just loading Windows is required.  You also need to install motherboard chipset drivers and then device drivers.  This sounds like your problem.   I don't know about going back to "old".
My hard drive on my Inspirion 1525 recently crashed and had to be replaced. Today I experienced a software problem with Vista and had to reload it, which I did from CD that came with the computer.  However, it is not working properly and I cannot get an Internet connection -- it says "No network adapter."  I attempted a Factory Image Restore with F8 at start up; however, I guess due to the hard drive replacement, that option was not available.  Now I am stuck with the newly loaded Windows but I have my old version in Windows.old that I would like to go back to.  I tried to copy the old directory over the new but with no luck.  Is there a way to get rid of the "Windows" and replace with "Windows.old"? I would appreciate any advice. Thank you
Restoring Vista Windows.old