On a couple computers, I had an issue where Excel would take upwards of 45 seconds to open. It would take this long if double clicking on an excel file, or just launching the program directly from the start menu. I found that if I disconnected the network cable, excel would launch instantly. I verified all the plugins were disabled but just couldnt manage to clear up this problem.
Today I decided to wipe it out once and for all. While searching the internet I came across a post on superuser.com. One response, buried among the countless responses telling you to turn off any add-ons, referenced a registry key where auto-recovery information is stored. For the poster, deleting this key solved the problem. He listed the location as:
I didn’t have that key, but found it in another location.
I deleted the key and found that excel now opens instantly.