I am working with excel a lot. I wonder why sometimes it starts eating 50+% of my CPU slowing everything down even when no calculation of formulas is happening and I didn't start any action! Funny thing is that usually this stops when I close one of the opened workbooks and it absolutely doesn't matter which one. Even some which I opened 2 hours ago and didn't touch since - if I close it then suddenly Excel stops being crazy and is usable again!
The almost guaranteed way to make Excel super slow and overload CPU is a simple pressing of Ctrl+C. Things don't get calm until I paste it somewhere or press Esc which is quite often very hard when everything reacts so slow at that time. It happens to me and my colleague as well with various workbooks and it does not seem to be related to any specific file as we work with many and create many. Any ideas?