Ankhi,
The only Dell notebook I was able to find which came in a "1500" model number designation is the
Vostro - is that your computer?
If so, I'd recommend downloading the newest available drivers for your video card model from the page linked above, and installing them in compatibility mode for Windows Vista. To do this, right click on the program .exe and open the Properties menu, then navigate to the compatibility tab and select "Run this program in compatibility mode for..."
If, in fact, you have an nVidia video card (as seems like a possible configuration for your notebook model), you can install the newest Windows 7 drivers from
here .
-Alex