Guitar Tracks 2 Not Compatible w/Windows 7 Home Premium What do I do

I used to have either windows 98 or XP I forget, but it doesnt work in Windows 7, had it installed, but wldnt load right mixer was blank, so I deleted it. Now Im trying to reload, not recognizing my serial number, and saying a version of cakewalk is still running on ur puter, ect ect....yet theres no listed cakewalk program to uninstall. Please help me Ive got tunes to record and am stuck!!!