I suddenly am stopped every time I try to enter data in an Excel worksheet. Even a new, empty one won't allow me to put a single number into it, giving me the "Visual Studio Just-In-Time- Debugger" message (attached). I've been using Excel for years, and use Acrobat to make printouts and booklets. In pursuing the problem, I followed a lead that led me to the Acrobat PDF Maker Office COM Addin and, having misunderstood what I had read in a problem link, I deleted it. I finally reinstalled it with a bit of torture. Still can't feed numbers to Excel. I tried uninstalling Visual Studio 2017 which I had installed late last year experimentally. Tried to uninstall Acrobat 11, wasn't allowed to, so I reinstalled over it. Uninstalled Office, reinstalled it. Still can't feed numbers to Excel. My laptop is still on speaking terms with Excel, and I can get most of my work done there, but there is obviously something wrong with this desktop. My questions are: (a) what other programs are there that insist on having JIT warnings, (b) how can I turn off JIT warnings, or (c) where is there a fix for this sort of problem? Also, what are other JIT debuggers which could be enabled?