If we install windows 7 64 bit OS can we run all 32 Bit Apps or only some? I'm a little confused as I know some do but I don't believe all do. Can someone please clairify. I would like to only use 64 OS's from this point foward because of the Hardware advantages (mostly memory usage) but I need all the various software to work so we are still using 32 bit OS. Can I switch and suggest all clients switch as well? Thanks for the help Robert Wiggins

Not all 32-bit apps will run on a 64-bit OS, but most will. Any app that has a 16-bit installer won't run (mostly very old apps). Any app that calls 16-bit routines won't run (again, mostly very old apps). Any app that relies on the Windows 32-bit hardware driver model won't run (usually games). Any app that tries to run its own hardware drivers won't run (usually device utilities). It really depends on the app itself. When in doubt, contact the app manufacturer. A common misconception is that if you run a 32-bit app on a 64-bit system you'll have all the memory available that the OS can address. This isn't true. 32-bit apps are still governed by 32-bit addressing - ie. the old 4GB limit, meaning that if your computer has 16GB of RAM, your 32-bit app can still only use 4GB max. The advantage is that none of that 4GB will be taken up by device drivers and such as it would have been on a 32-bit system, thus allowing your app access to the entire 4GB. At least that's been my personal experience. I'm sure someone will point it out if I'm wrong.

Hi, Thanks for posting in Microsoft TechNet forums. Generally, most programs designed for 32-bit versions of Windows work just fine on computers running a 64-bit version of Windows. To install the programs, you can first check in Windows 7 Compatibility Center. For more information about 64 bit Windows, please visit: Understanding hardware and software for 64-bit Windows Taking the mystery out of 64-bit Windows Best Regards Dale Qiao TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Thanks to all for the info. it helps agreat deal. Robert Wiggins