HTC not recognised in windows

[redsquash]

I have no knowledge of mobile phones.I bought a second hand HTC desire. Is there an installation disc or something I should have as windows xp doesn't seem to recognise my ph.

It only shows in control panel that H drive is connected. Opening that drive shows no content .
I was told the ph was unlocked but how would I know?
The telstra logo(ph carrier) also comes up on startup .
I don't have a sim card installed but that shouldn't make a difference?

 

[amlothi]

After connecting your phone via USB, you need to tell the phone to allow use as USB storage device. On your phone, drag down the status bar from the top of the screen, find the USB connection, and select "Mount as USB storage" or something like that.