Ridiculous problems with VPN

I am going out of my mind here trying to set up Hamachi on this computer. Every time I try to run it an error box pops up and says "failed to connect to Hamachi network adapter" and then it just closes. I've tried so many different things to fix it, such as:

-Deleting the application data so it could make a new folder (this is when it started to completely stop working whereas before I did a couple minor things to try and fix connection problems, and after this it's been the same ever since)
-Making sure Windows firewall is completely off
-Making sure DHCP Client and Network Connections services were running during the install
-Disabling and re-enabling Hamachi in device manager
-Disabling AVG and Spyware Doctor to make sure it wasn't blocking anything during the install or something
-Running a different VPN program to make sure it wasn't just Hamachi (I get the same error)
-Downloading and running the Winsock XP Fix
-Running the system file checker (sfc.exe) with my Windows disc
-Disabling my onboard network card in BIOS (it crapped out on me a while ago so I got another cheap network card and put it in, but I only recently learned how to turn it off for good, thinking it might've been causing the problem, but of course not)
-Re-installing Hamachi COUNTLESS times throughout this whole ordeal

NOTHING I've tried has worked so far, and it's just insane. I manage to run Hamachi just fine on my other computer on the same network (it has mostly the same software and the same operating system and everything, only real difference between mine and that one is the hardware) and that works but it would be really nice if I could get it to work on this computer too.

Does anybody have ANY ideas to fix this sort of thing? The only thing I can think of now is some sort of software or driver problem, but I can't IMAGINE anything on my computer now that would cause stuff like this. If you're just going to say "re-install Windows or maybe even reformat your computer" then that's really NOT helpful because I wanted to see if there were any possible solutions before it came to that.