No more midi input


I’ve been using Grand 3 64bit in WIN7 environment. From yesterday, the midi yellow light stop flashing, hence Grand 3 thinks no midi data. But when I run cubase 5 and other midi programs everything normal, they are getting all data from my midi keyboard. I’ve removed the Grand 3 and reinstalled it a few times now, I even tried to run 32-bits version. It doesn’t work anymore. Anyone could advise what should I do next. Thanks.