When I boot up my Acer Aspire 5732z in the morning I get a small pane which tells me it is 'Unable to start the program ' because sysenv.dll is missing and that it should be reinstalled '

Everything on the machine works but it pops up again on reboot.

There is no indication which program cannot run so the popup must I think be part of win7

My question is ...how do I go about finding sysenv.dll and how do I reinstall it?

All help will be acknowledged

John