Seagate Freeagent 500 GB does not detect

Dear ... I have recently purchased Seagate's Freeagent External Hard Drive (500 GB Capacity). It was working all right for about 10 Days, but now I face a peculiar Problem. This drive does not show in the My Computer at all. I tried connecting it on several (about 6) other PCs and Laptops and this is what exactly happens - 1. When I connect it to a fresh PC where it has not been connected earlier, The PC starts the New Hardware found procedure. 2. It shows, "New Hardware found", "Seagate Freeagent Found" etc., then suddenly either the PC hangs or simply reboots. 3. There seems to be nothing wrong with the External HDD's Power Supply or the USB cabling, as both have been thoroughly checked. All the above PCs/Laptops were loaded with Windows XP + Service Pack 2 The HDD's LED glows as usual and does not sho any power problems. I feel that there is some virus activity that stops this Drive from giving access (Maybe some boot sector Virus) Pls help. With warm regards, Manjit Singh New Delhi