NvCpl.dll error and Conexant mode registry not found messages

I am getting the following error message on one user account with non-admin
priviliges:

Loading Error NvCpl.dll Access is Denied.

The error pop-up shows up upon logging on and occasionally while accessing
sites on the Internet such as MySpace and YouTube. However, I don't have the
problem on my own account (with Admin privi's), and on two other user
accounts. I am running a WinXP SP3 w/MS Office 2003.

The other question is that I ran a modem test on a Conexant 56K internal
modem for a Dell Latitude ATG D630 laptop running WinXP Pro and the modem
passed all tests except:

[Registry Information]
Register:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entversion\unimodem\Devicespecific\Conexant HCF ^
Register: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\P CI\VEN_14f1^
Register: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Servic es\Winachcf^

Can anyone guide me in the right direction?

Much appreciated.

Angelo