Lately I've noticed that there's been a dramatic increase in the amount of hard drive space useage on my computer and I tracked down the culprit to a folder Studio installed in my C drive. The C:\Render folder is currently at 18 GB and climbing. It appears to be storing some kind of odd backup files for every project I've ever done. At this rate my hard drive will be full by the end of the month! Do I need to keep any of these files? If I completely clean out this oddball folder am I going to run into problems if I ever wish to revisit my older projects? And why do I need this bloated backup database anyway? Is there a way for me to disable it so that Studio no longer stockpiles here?

 It may or may not be relevant, but I originally installed Studio on my C drive, then uninstalled it and reinstalled the program on an external hard drive.

1) Go to: Folder Options / View / Hidden files & folders & Uncheck: "Do not show hidden files & folders".

2) Go to: Documents & Settings / All Users / Application Data / Pinnacle Studio / Data / Render / Aux Files & Delete those.

I originally installed Studio on my C drive, then uninstalled it and reinstalled the program on an external hard drive.

Studio should be Installed on your OS Drive C:

 

These are Auxfiles and they do build up in a short time with frequent use of Studio. 

You can also click on Toolbox and click on the Folder Icon for Aux files and it should show you a folder list of with Render Folder highlighted. Right click on it and choose open/explore and then delete its contents.
 

Thanks for the tips. So long as it's okay to delete them, or they'll self-destruct on their own accord, I suppose it's nothing to worry about (I manually deleted 'em this time). Also, I usually have tried to set the aux files to be created in the external drive where Studio is installed, and I've noticed that there's an F:\Render folder as well. However, the files there appear to have already auto-deleted. If I run into anymore weirdness, I'll probably go ahead and reinstall on my C drive.

You might run into some problems having your render folder on a external drive as drive letters on them change when plugged to a different USB port or have problems if they are connected when Studio needs to store cache render. Choose a local path that is easily accessible like C:\. That should be easy to manage.