Monitor turns off, GPG won't open

I installed GPG for Windows on my laptop and integrated it with Thunderbird, no problem. I tried to install it on my desktop and it’s not working. Problem #1 is that GPG shuts the monitor off and on every time it performs an action. Problem #2- it won’t send encrypted email, says that key is not valid. When I click on Winpt.exe to reimport the keys, it does not open. Any help appreciated.