Hello and welcome to the forum!
- When you say you blew your PC, did hardware die or did you reinstall windows 7? Have you swapped out a motherboard or network card?
- Did you install the drivers for network card/motherboard? Does device manager show any problems with any devices on your system?
- If your license is locked to your MAC address make sure that you don't have other network cards that Creo may be trying to use the MAC address for (i.e. dual LAN or wifi) as opposed to what is in the license.
- Did you do a clean install of the OS or did you upgrade over top of the old one?
- What are you using to start Creo...shortcut icon, etc.?