Everything was fine and then suddenly i've got this problem. It doesn't go away with restart, I haven't tried to reinstall the app. Other threads with this problem weren't complete so i writing it now. I use Win 10
I'm not the author of the HWiNFOMonitor gadget, so I can't give a reliable advice.
Windows 10 doesn't have embedded gadget support, so you need a 3rd party tool for that. Which one are you using, could the problem be perhaps there?