Sony VGN-TZ10 Manuale Utente

The above procedure involves system recovery. Note that the applications and data you added on the primary storage device (the built-in flash memory 
storage or hard disk drive) before deleting the VAIO Value-added contents will all be lost. See the online Specifications to find about your storage device 
configuration.

You cannot delete the part of the recovery partition (approximately 1.5 GB) where Windows Recovery Environment (WinRE) is installed.

Once you have deleted the VAIO Value-added contents, you need the recovery disc for later system recovery.