Windows 7 Mixed up my code stickers

I have four "upgrade stickers" for Windows 7 that I received when I bought Vista 64 Ultimate earlier this year. Unfortunately I did not install the stickers to Window 7 stickers to the various computers (or put them on the case sides and used the same case so they are all mixed up now that I bought and installed a couple of new fans and CPU coolers for the CPU's and I am lost as to which computer the codes go on. Now I need to repair one of my computers and I don't know which goes to which. Is there a way to "unregister" each computer and then attach the correct code to the computer case itself. This is a self installation so Microsoft doesn't offer any support. If there isn't a fix for this, I'm switching to Apple and just making the non working machine into Linux a machines and I'm not a gamer and my wife can use the others for her business. Windows offers no support for this kind of problem and although it is my fault, you would think they would have a customer support number for purchasers of a certain number of copies. We are replacing two old Vista Machines and I bought a backup for each of us as my wife's business depends on her Windows operating properly and I maintain the network so I can offer support when she needs it.

Any suggestions on how to make sure I get all of these stickers on the right machines. I broke one Windows 7 OS already and had to call Windows and just picked one out to install since the man in India couldn't help one iota and didn't want to even listen, he just gave me a code over the phone, and now the thing won't work at all. Seems they allowed me to repair it but when I tried to remove a partition on it, I ran into major problem. It almost seems like they had me pegged as a copyright infringer as the drive was not correct since when I removed the D partion, the C partition disappeared. ?? The OS on the C drive was completely gone.

Any suggestions. I need to get this non working machine running.

(Not to mention the gaming machine that I bought an upopened copy of Window 7 Ultimate that I am going to send back to Newegg if I can 't get these stickers straightened out. So much for doing things in a rush but this was the first time I'd built a computer in a long time and Windows used to not have such catches. No wonder people are switching to Apple).