What is the exact make and model of the computer?
The manufacturer will have your drivers if you do not have a driver disk.
Did you use the OEM XP disk to Recovery the computer?
As to Access Denied try this:
http://support.microsoft.com/kb/308421
If you ran a full recovery it is amazing that you can still see old users and data. Usually this would have wiped out all data unless you just ran a repair option.
Anyway most likely all programs will have to be reinstalled.
If necessary (and assuming the data is still there) you can slave this drive in another computer in order to extract data.