If Windows 7 Was Preinstalled your SLIC should be already 2.1... You Should Verify using the SLIC Dump Toolkit.. If You Use a Windows 7 Ultimate DVD that Came from dell it will automatically install the dell certificate and pkey but still it will not be activated because most likely the Dell certificate would not match your HP SLIC.. all you have to do is get an hp certificate and install it along with a OEM:SLP key of your choice (since HP isn't available yet...) If your preinstalled windows 7 is still present I would navigate to "C:/Windows/System32/OEM" and backup the present certificate for this one is the one that matches the slic in your bios.. (to save you from the doubt that the certificate will not match or save you time because you don't have to look for a matching certificate..) ps. sorry for my bad english..
Thanks for the info guys... @asphix I did search the forums, but since I'm new to laptops, I didn't know there is tools available for backing up your activation.