So what the heck is MSO cache anyway?

MSO actually stands for Microsoft Office, you might have noticed this folder in your program files directory ( you'd only be able to see it if you have enabled your computer to view hidden files and folders). If you have Office installed on your computer the MSO allows you to modify Office installations without having to insert the CD again. Is it safe to delete this folder? Absolutely, after all on my computer it ended up taking a good 500MB of my harddrive space.