Perhaps because 64bit drivers aren't available for a device being used or perhaps because the 32bit software will only run well under 32 bit system. That is rare but does occur.
I've been pleasantly surprised that the 64bit drivers and software that I use work better than the 32 bit versions.
My Computer
At a glance
MS Windows 7 Ultimate SP1 64-bitAMD A10-4600M6.00 GB Dual-Channel DDR3 @ 798MHz (11-11-12-28)AMD Radeon HD 7660G
Computer Manufacturer/Model Number
Toshiba Satellite S875D-S7239 laptop
OS
MS Windows 7 Ultimate SP1 64-bit
CPU
AMD A10-4600M
Motherboard
AMD Pumori (Socket FT1)
Memory
6.00 GB Dual-Channel DDR3 @ 798MHz (11-11-12-28)
Graphics Card(s)
AMD Radeon HD 7660G
Sound Card
High Definition Audio Device
Monitor(s) Displays
Generic PnP Monitor (1600x900@60Hz)
Screen Resolution
1600x900@60Hz
Hard Drives
SSD 119GB Corsair CSSD-V128GB2 ATA Device
Keyboard
Standard PS/2 Keyboard
Mouse
HP Wireless Optical Mobile Mouse Model FHA-3410
Internet Speed
What the local pub, local coffee shop offers.
Other Info
Optical Drive:MATSHITA BD-CMB UJ160B ATA Device
Also have an Asus ha1002xp netbook with Win 7 Ultimate installed.
Since you have to do a clean install to change the bit-rate as there is no other option, have a look through these tutorials linked below and be sure to post back with any further questions you may have and to keep us informed.
"I am a gamer and have games I really enjoy that run erraticaly on a 64 bit OS."
Also I am a Ham (Amateur Radio) operator and much of the software I like was initially designed for 32 bit machines.
I thank karlsnooks for his definitive answer. That's what I wanted to know.
I will do a clean install.
Now I have to decide if it will be XP Pro or Windows 7 Ultimate 32 bit.
Thanks mate. I guess that is a more logical solution for the long-run.
Do you have any suggestions on where to get the best deal on 32 bit Win 7 Ultimate ?
Just be advised that the OEM versions are forever tied to the first motherboard that they are installed to and cannot be legally moved to another mobo if the need ever arises.