Have you tried installing the packages via your other HD? Keep them in the root, not in any folders. Your positive you have v4 FW for the PS3Key? Should work with v3 tbh but v4 is the latest. What are you trying to install?
If you are trying to update games you can do them from the games themselves by downloading the updates via internet. But i'm guessing you are trying to install Open Manager or so?
EDIT: Oh and also did you get a serial/verification number with your product? If you didn't, you'll need to request one from the company you got it from. If they don't have it, then thats a bit fishy
Original PS3 + Slim PS3 - 3.41OFW - 640/320GB - 3 DualShock 3 Controllers - PS3 Remote - PS3 Keypad - x2 Move Controllers/1 Navigation - Jailbroken - x3 PS3Key v4.0 - Maximus AVR USB.
2 Fat PSP's - PSP1000 - OFW 5.00 - PSP1003 - CFW 5.00 M33-6
Original PS2 - Chipped
2 PS1's - Chipped