I know this thread is old. Anyway, the way to install the drivers for the ralink rt2500 is to download drivers (RT2500_Wireless_LAN_Card.zip.......37.9 MB) from driverguide.com so you can have the inf files. Once you have the inf files it's ok to uninstall the drivers from device manager and the application from programs and features and restart your computer. Once you are promped to install the drvice when your computer restarts, brouse to the folder where the drivers are located and follow the steps to install it. The computer will automatically install the drivers. After the drivers are installed, all that has to be done is to connect to the wireless card by configuring it in the network and sharing center. To be sure that the wireless connection is working open a web browser and go to a website. This wireless card does not bypass any wep entries you need to enter for a secured connection.
If you want to install the wireless assistant from the manafacturing website, it might work with the installed drivers, but I don't want to try my luck and ruin my connection and have to start over again. So, I did not try that. I also did not try to simply use the exe setup file to install the driver and wireless assistant.