Not stupid at all! I wish I had asked when I first saw PF86 (my own
abbreviation) about 5 years ago when I first got Windows XP x64.
Since this PF86 folder was new in x64, I assumed that it was for 64-bit
apps. By the time I learned the truth, I had things hopelessly tangled
between the two PF folders. The fact that I was dual-booting Win2K and
WinXP 32-bit made the situation even worse.
For example, from Win2K, I installed Office in E:\Program Files\Office.
Then I installed Office into E:\Program Files\Office, again, from 32-bit
WinXP. The Office Setup program made its entries into each separate
Registry, but shared the executables and settings between the two Windows
installations. This worked fine for several years. Then came WinXP x64.
Again, from x64, I installed Office into E:\Program Files\Office; it was
several months before I learned that it should have been in the new
E:\Program Files (x86)\Office. That would have been the end of file-sharing
because all Win2K and WinXP x64 disagreed as to which folder was E:\Program
Files. :>( Since there was no 64-bit Office then, I guess there was "no
harm no foul", but my confusion was entirely understandable, unnecessary and
avoidable. Why didn't Microsoft simply keep the old PF for 32-bit apps and
create a new PF64 for 64-bit apps?
In case you are wondering, the "x86" comes from Intel's 8086, 80286, 80486,
etc., series of CPU chips, all 32-bit.
Only now are we beginning to beta-test the first 64-bit version of Office,
named Microsoft Office 2010. Maybe there will be a flood of 64-bit apps
soon and someday the PF86 folder can be retired.
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
Windows Live Mail 2009 (14.0.8089.0726) in Win7 Ultimate x64