On your computer click on the Start button.
In the Search window type in %temp%

This will bring up the Temp folder. Delete all the files in there. The easiest way would be to Shift-click on the first file, hold down Shift, scroll to the last file, and then Shift-click again. Sometimes the delete process will stop because of an open file - you need to click Skip to continue with the delete.
Are you working on workshared / networked file? If not, then all you would need to do would be to get rid of backups. Backups have numbers at the end of the file name. Keep 1-2 of the newest backups, delete the rest. Clear Recycle Bin. Reboot. Let us know how it works.
Rina Sahay
Autodesk Expert Elite
Revit Architecture Certified Professional
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