Try and use the program compability wizard and maybe visit the manfucaturer website and see if there is any known problems with those games running on XP.
Okay can you let us know a little more about this problem, because im not fully understanding what is happening here. Provide as much detail as possible and I will probally be able to assist you.
No its not possible. I think if you REALLY wanted to do this you would have to take apart from actul ship and tinker with some electrical stuff and rewrite the BIOS code to include the new serial number. Edit: Dells have a splash screen which displays their serial numbers and such, but I'm not aware of how to do this.
Try to redo the entire thing. I know it doesent seem helpful, but i had this excact same problem and it workd when I tried it the second time. if not, give us a PM and i'll try to help ya out more, or post ir here if you wish.
I personally tried 7, didnt like it, and wanted to go back. I did a search on google, and I found it. I have the msn 6.2 installer on my HD, so if you want it, give us a PM and id be more than happy to send it to you mate!