I am using Win 7 Ultimate 32 bit but want to change to 64 bit. Is there any way to do this other then a new clean installation?

No.

Changing to 64 bit version require reinstalling Windows

Unfortunately reinstall is the only way

Wot they said.

yep reinstall but at the same time you could update to windows 8

Check that your cpu is 64 bit architecture first.

You must have a really specific reason to want to do this?

All you gain is the computer seeing more RAM - only a heavy user/program would really beneift from 64bit?

You must have a really specific reason to want to do this?

All you gain is the computer seeing more RAM - only a heavy user/program would really beneift from 64bit?

Yes... Runs C5 and other graphic programs... Has 8gb installed but not available.

So I will be making a clean installation of Win 7 64 bit.

You must have a really specific reason to want to do this?

All you gain is the computer seeing more RAM - only a heavy user/program would really beneift from 64bit?

Yes... Runs C5 and other graphic programs... Has 8gb installed but not available.

So I will be making a clean installation of Win 7 64 bit.

If with C5 you mean Adobe Photoshop C5 …. you not need to upgrade your operating system to 64-bits. Adobe has no 64-bits Photoshop available so you're even with MS Windows 7 x86_64 limited to 3.25GB memory....

You must have a really specific reason to want to do this?

All you gain is the computer seeing more RAM - only a heavy user/program would really beneift from 64bit?

Yes... Runs C5 and other graphic programs... Has 8gb installed but not available.

So I will be making a clean installation of Win 7 64 bit.

If with C5 you mean Adobe Photoshop C5 . you not need to upgrade your operating system to 64-bits. Adobe has no 64-bits Photoshop available so you're even with MS Windows 7 x86_64 limited to 3.25GB memory....

It's natively 64bit. One of the bigger changes for CS5. What makes you think otherwise?'

Some cs5 programs work natively in either 32 or 64. Some..I think premier and after effects...may be wrong... are only 64 bit now.

All will be able to use the full amount of ram if on 64bit or 3.something on 32bit.

Backup everything first since you will lose everything on the main harddrive. Then upgrade to win7 64bit.

Ignore win8 unless you already like it...some do but most dont. It is radical unnecessary changes designed for tablets and forced on desktops.

Just the fact the OP wants to utilize 8gb RAM is enough reason to swap to 64 bit

On a personal level I have felt that 64 bit seems a little more stable (possibly the ability to address 3.5+GB of RAM). For the record even CS6 has 32 bit and 64 bit versions with the exception of Premier Pro and After Effects. CS4 has full 32 bit support and the CS4 versions were packaged into CS5 Master Collection.

Yes do watch that some programmes that run under 32bit may not with 64bit