DigitalVolcano Software Support

how do i know what to delete and wont harm my compter

If you store all your own documents, pictures etc. in the default "My Documents" etc. folders, then you won't really lose anything if you limit the search to those folders.

Scanning the complete (C:\) drive could be harmful, because it also contains folders with necessary system files.

You could also store your personal files on another partition or drive, to completely separate data from system (files).

Good advice.

If in doubt, don't delete. Don't run DC on system folders.

The same could be applied for installed Programs.

If you create a Program Files folder on another partition or drive, you could also separate your own custom programs from installed system programs.

This could also prove convenient for separate backups of system files and custom programs backups.