This is how I set up my backups so this never happens.
http://reaperblog.net/2013/07/reaper...-backup-setup/
I use an app called CronniX to automatically clean up the temp folder, moving anything older than a week to the trash. I think this can also be done with a combination of Automator and iCal.
You can probably set something up similar on Windows with the task scheduler.