Error msg on desktop...hlp plz

[jovianne]

Every time I start my computer I get the same pop up error message on the desktop "Windows Explorer has encountered a problem and needs to close". Followed by another one from "Symantec Security Driver Install Monitor"

AppName:Explorer.exe ModName:msi.dll

I don't understand alot about the computer so I am very lost here. I don't know how or what to tell you except what I have writter above. I tried to do a system restore and that worked until I had to turn it off and then when I turned it back on the next day there it was again. So now I have to do a system restore each time I get on the blasted thing. It was running like a top till last week when the power went off. It was not a storm, no lightening, the power just went off then back on.
I really hope you guys can help me. TIA
Jovianne