W7 64bit

If you're talking about changing the operating system, you have to reinstall from scratch.

If you're talking about running a program in 32-bit mode vs. 64-bit mode on a 64-bit version of Windows, you just run the appropriate program. For example you click on the "Internet Explorer" or the "Internet Explorer (64 bit)" icon.

Sorry I was not clear in my OP. I actually wanted to be sure my W7 ultimate will run at 64 bit mode when I launch Adobr Photoshop CS5 which can work in both 32 and 64 bit.

If your Windows is 64bit, then it will run both 32 and 64bit programs just fine. It comes down to the software itself. Are you sure Photoshop can run in both modes? Isn't there a separate 64bit version?

I can't speak for Photoshop CS5, but for CS4 the start menu contains two icons:

Start -> All Programs -> Adobe <edition> -> Photoshop CS4
Start -> All Programs -> Adobe <edition> -> Photoshop CS4 (64-bit)

...so it's just a matter of choosing the appropriate icon to click.


If you're wondering how to make sure the appropriate program is started when you double-click a file, then right-click the file, choose "Open With...", and then click "Choose default program..."

Thanks. I found the 2 icons in CS5 just like you said. In future I will launch Photoshop by clicking the correct icon. Instead of double clicking an image file.

If you navigate the Start menu to the correct icon you can right-click it and select "Pin to Taskbar" - that'll leave a copy of the icon on the taskbar where it will be much easier to start up.

Once it's been started you can drag-and-drop files from Explorer onto the Photoshop window to open them rather than having to navigate Photoshop's "File -> Open" menu.