Capita… avere più di 2 TERABYTE liberi sull’HD e non riuscire a fare i test… 
The Disk IO test fails on the disks with free space more than 2 tera bytes. It fails with an error code 0x06 and error message “The handle is invalid”. The only workaround for this problem is to reduce the disk space to less than 2TB. This test issue will be fixed in the future WLK releases.
Fonte: Disk IO test fails on disks with free space more than 2 tera bytes