According to the workbench release notes Line6 andy published in the "Popular Documents" section, Workbench V1.58 supports the Windows 64 bit operating system unless you are using the Variax to computer hardware interface shipped with the boxed or retail version of Workbench.  See below:

v1.58 Release Notes/Known Issues

What’s New?

• This version of Workbench software adds support for POD X3 Pro

• This version of Workbench software adds support for 64 bit operating systems.

Known Issues:

*    The 64 bit drivers only support the Line 6 Variax PODxt Live, POD X3 Live/Pro, Vetta I (equipped with the VDI interface), and Vetta II.  The Workbench Interface hardware is not supported on a 64 bit OS.

yes   we know  that   its  the  usb driver  thats  needed  the   software  works  fine.  cant  connect  it  to the  guitar  with  the  workbench  hardware,  usb  does not  recognise  the  workbench  hardware,

you have  to find the  place  to make  a  support  ticket  on there  site. i never  needed  one   soi dont  know   exactly  where  it  is  but  it is  in the  support  section  or you can call them

818-575-3600 us  or _44(0) 1327 302 700  gb

yes  by all means  put  in the  feature  request  .   i think  we need  some  line 6 personnel   to push  this   problem  to a  soloution  as well  though. so if  some  of  you line 6  moderators   could  get on board  with  thism   maybe  take  a  big  stick  to  the   programming  section  and  stand  over  them  while  they   write  the  driver(shouldnt  take  more  than  an  hour)  then     this   problem  will  be  solved.