http://www.hp.com.csy/products/turbo.html reports...
Failure to install either the SUBSYS or the appropriate XL will remove
TurboSTORE/iX II or TurboSTORE/iX 7x24 from your system, leaving you
with FOS STORE functionality.
^^^
Well maybe the 'READ BEFORE INSTALLING' instructions were translated
from a non-Roman-8 character set before being FTP'd from the web page.