install shield

[sis33597]

My sister just bought a new HP computer and I am trying to help her set it up. It came with Windows XP.We installed a scanner and printer, both HP, and they did not work right the first time so we had to uninstall and reinstall them. We have both of them working correctly now but when we try to install a game, it starts the install process and then we get a message box saying the the uninstall shield it running and we need to cut the uninstall shield off and then try tto install the game again. I can not find were to cut the uninstall shield off. It does not show in the taskbar either.Can anyone tell me how to shut the uninstall shield off???

Thanks
Janice