Thanks for the reply. I've done what you're suggesting. i have already selected in settings-connect to pc- default connection type- disk drive and also in applications-development-usb debugging mode- disk drive, but nothing happens. I just get something in the notification bar that says usb debugging mode connected and that's all. i installed the latest htc driver, i thought it might worked, but i had no success.
Go to Settings, Connect to PC, and choose Charge Only by default connection type. Tick ask me box. Plug in the USB, and wait until the box to choose how you want it to connect. Click Charge over USB. If that works, then wait for your computer to load. Some computers take longer. If that does fail, get a micro-usb cable, Maplin or Amazon should stock it. Try get a new cable, as I have trouble with a USB cable which keeps disconnecting, then reconnecting. Try that, and see how you go.