Photoshop 7.0 won't open; scratch discs are full

Let's start a bit back.  I had a HD failure, they only had a 2TB hard drive available (mine was a 1TB).  I had my apps and data cloned over to the new HD.  I  suspect that something went wrong with the cloning or that during an abrupt shutdown, a file on the registry became corrupted.  BTW, Staples guy said 2TB was not the problem.   I am not sure what he did, but he said that it was a corrupt file on the registry.  He said that he used a way better uninstall tool than provided with my system to ensure all files were GONE.  He then reinstalled PS 7.0.  I suspect that he was correct to some extent.  I have heard that sometimes when you uninstall, not all files get uninstalled.  If the evil file in question (LOL) remained corrupted on the registry regardless of using the provided uninstall utility, then reinstalling the application would not work as this file would not be overwritten with the non-corrupted version, but be bypassed in the re-install because, heck the file was already there, wasn't it?  Anyway, I don't know what he really did, but I do know that I have to Run as Administrator still and I didn't have to before, but I am not messing with it.  Try...a uninstall utility from the manufacturer to get ALL files gone and then try reinstalling....