How 2 recover contents of a inaccesible drive

Hello,

I was not able to access my drive D, it used to give me d msg "inaccessible, disk corrupted..." then I downloaded one s/w named test-disk6.0 and tried with it and now My computer is not at all showing drive D, in disk management also its not showing drive D, and its showing tat area as unallocated. I downloaded 'the undelete company's Ntfs Data Recovery v2.4' its showing me the contents of drive D but i am not able to recover them as i am using a demo version, can somebody provide me other alternatives... i dont want 2 purchase d s/w its costly. Plz help