Before you uninstal be sure you have downloaded the right driver and that your computer can install it. You can run the setup for the downloaded driver and cancel it just before agreeing to install.
Do you know how to boot into safe mode?
There are usually two ways, one through msconfig and the other via the bootup (by pressing an F key, usually F2 or F8...mine is F8).
Once your in safe mode, go into your device manager and expand your Display Adapters.
Right click on the entry for Nvidia Geforce Go 7150M. You should have the option to uninstal there.
Once its removed, restart the computer. Even if the computer doesnt prompt you to do so, still restart it.
You can then install the new driver. I would usually recommend making sure all traces of the previous driver be removed, something thats not easy to do manually.
it should be alright. If not you can try again, this time running a third party software program like Driversweeper to remove all traces before installing the new driver.
When you finished installing the new driver, make sure you turn off Safe Boot in msconfig if you set it from System Configuration.
Hope this helps
Just in case your not sure how to run Safe mode via msconfig, simply type it in your start/start search box and and the System Configuration program will appear in the menu. Run it and in the Boot tab of the configuration window, selec the tick box Safe boot. Click apply and restart the computer. It will remain in safe mode until you run the tool again and deselect it.
I would recommend using Msconfig just in case your not sure which F key to press when your comp starts up or you miss it.
Let us know how you get on.