I've played GW2 on this computer for months including last night. Today I turn it on, find the GW2 icon grayed out, and what would appear to be a windows popup (blue, white lettering) that says "This app can't run on your PC. To find a version for your PC, check with the software publisher. Initially it said "requires administrative approval to run this app". I right clicked the GW2 app and clicked run as administrator (I am the admin) but that only switched the message to the first one I listed above.
Running a full scan with windows defender shows no issues.
Today is GW2 update day, so the other computer had a longish download but ran fine. I'm only emptying bags and running chest campers. The troubled computer won't even get into GW2 login screen and start the download. I'm on lunch and am pot of troubleshoot time atm, so thought to see if others have had this and what the answer is. (corrupted windows, corrupted GW2, malware, etc)