Applications running slow

I have a Dell Poweredge 4400 with 1gb memory and plenty of disk space with one processor. Since moving the applications from Novell 3.12 to Windows NT 4.0 w/SP4 applications are running slow as much as 5 to 10 minutes.After running perfmon the CPu-3%, Network -3%,Disk time -low memory usage low.What else can be done to perk up the apps?