I downloaded the gDEBugger from gremedy over a year ago, with their one year free license. The license has since expired and their site says that I'll be presented with the option for 1 year free license the first time I run it after install. This doesn't happen when re-installing, it just tells me the license has expired. How do I get a new license? I use this regularly for debugging shader problems and performance testing my game.
Try deleting the C:\ProgramData\GraphicRemedy directory, run gDEBugger again and ask for a new temporary license.
If you are using linux, check the .gremedy directory and remove the existing license file.
As of December 2012, Gremedy has released a version of their software with the license mechanism disabled. It's available for download here.
The gDEBugger from gremedy appears to have been abandoned. Their forums have been down for a while and the last release on their site was December 16, 2010 with version 5.8.
AMD now hosts AMD gDEBugger. Their website has a release from April 20, 2012 with version 6.2 (as of this writing). The system requirements now list 'The latest AMD Catalyst driver'. The program will still operate without an AMD card, however kernel debugging will be disabled.