name of program

There is the user manager MMC or if you're looking for something external.
Goto http://home.eunet.no/~pnordahl/ntpasswd/

There are instructions for creating an offline nt password & registry editor (which you can run while you're logged on).

Good Luck
0bytes

runas.exe will allow you to run a program in the context of a different user account.

Gavin

What functions are you looking to perform??

You can access a remote system via Computer Management by going to Action -> Connect to another computer...

You can access hidden shares by going to Start -> Run -> typing in \\computername\x$ or \\IPaddress\x$ (where x is the share you want to access.

You can also access a remote registry...

If you're trying to access a system by remote control, you'll need 3rd party software (i.e. PcAnywhere, VNC, etc.)