Hi, I have installed Microsoft Windows Vista Business 32bit on a Dell Precision T3400 workstation and I also configured Group Policies for Non Administrators. Basically I disabled removable drives, 'C' and 'D' only for non administrators. After done editing in GP, the system was precisely secured and I am able to access to Administrators account and copy some stuffs from my local drive to my thumb drive. However couple of days later, I am not able to use my thumb drive or other external drives in Administrator account, It shows that 'inaccessible'. But i can access to local drives 'C' or 'D'. Then I have to redo the group policies and it will only last for 3 days. Thank you :)