I upgraded the RAM to 2GB. When I turned it back on, I received an error message and wanting me to choose F1 to continue, F2 to do something else and F5 to do something else I choose F1. Then I got a message that said that "No physical memory is available at the location required for the windows boot manager. The system can not continue We put the older 1GB stick back in and it too is saying there is no memory. Help.