Hi i have just bought a new radeon x1650 pro 512mb

When the card is properly installed and the system properly configured, you should at least be getting the POST screen, since that is not driver dependent. And Windows knows to go to the default standard VGA driver when it can't find specific drivers for a card. So we're looking at a hardware issue, not software.

Here are the troubleshooting steps I would take. Some would seem obvious and you've probably already tried them, but I like to be complete:

Is the monitor switchable betwwen two inputs? Do you have it set to the correct input (i.e. VGA vs DVI)? hit the selection button on the front panel, just in case.

Is the card properly seated? Take it out and put it back in. Also, oddly enough, reseating RAM can fix a lot of problems, even seemingly unrelated ones.

Is there an on-board VGA connector? If so, switch over to that and see if you get picture. Then go into CMOS settings and look for a video setting that would make the add-in card the default display. Or simply disable the on-board VGA.

Check the pins on your monitor connection, make sure none are bent.

If none of these get you a picture, I would suggest a defective graphics card.