Please follow these steps:

1. Open up US DataVault Backup Pro and then press "Tape Maintenance"
2. Select the tape from the drop down menu and press "Select tape drive"
3. Take the Bloc size and multiply it from your amount of RAM in your computer/server.

Example: 50 bloc size X 256MB RAM = 12800

4. Take answer, in this case 12800, and put in in page file size. You will find page file size, under "Preferences".