Can't get originally installed desktop back.

I just purchased a Dell desktop with Win 7 Home premium.  It came with a beautiful fancy desktop in Win 7 with a pinned task bar in addition tot he normal task bar.  It was charcoal with a great new look.  After a few days the machine suddenly shut down.  I have not idea why.  When I rebooted the machine would not longer accept the password so could not go beyond the startup. Apparently the hard shut down corrupted the passwaord file.  I had to reinstall Win 7 from the Dell Reinstall disk as a parallel install.  It runs fine now, after installing a new user, but I can't get or find the originally installed (as delivered from Dell) desktop.  Can anyone tell me what desktop Dell delivers with the Win 7 install and how to get it back?