Windows sql server

Sql server wont allow more than one login at a time per client, under W2K.But will allow numerous
logins under W9x. We were asked to run “regedit”. Open HKEY_LOCAL_MACHINE. Go to software, check if ComputerName and DatabasePath exist in the right panel. If yes enter the correct values for them, Otherwise create new keys(string value).
We did all that and still have the same problem.