I accidentally asked my ActiveSync to sync all of my calendar entries. It made my WM5 phone run out of memory. Then, I wanted to delete my calendar and start again.I searched all over the web for how to do this, and couldn’t find anything, so just in case someone else is looking for things like windows mobile erase entire calendar delete calendar file et cetera, I hope you find this!All you need to do is go into File Explorer, into My Device, and find a file called pim. This has ALL of your contacts and calendar appointments. You can’t erase it because its in use. Instead, rename it to pim2. Then do a soft reset. You can now delete the pim2 file, and that will free up quite a bit of memory.There, now I hope others who need this will find it!