A Computer freezing at Stratford upon Avon

We are with a Customer on St Marys Road in Stratford upon Avon, The customer has reported that the computer system here is Locking up, We edited the Registry Removed some Trojan Virus and Malware, Updated Drivers, updated Internet Explorer 7 to Version 8, The main issue here was a fake antivirus called PC Doc Pro V5 which had not installed properly and was causing the system to freeze.