Windows stole my F9 shortcut

As long as I've been using HeidiSQL, I've used the F9 key to execute a query or apply a filter in the Data tab. But since a recent upgrade to Windows, F9 now opens a Windows Search popup in the lower left hand corner of the screen. Has anybody else had this problem? So far I can't figure out a way to either disable the key in Windows, or assign a different one in HeidiSQL.