Can I install 32-bit "over" 64-bit?

I originally posted this question on another thread but I didn't get a respons. I hope somebody can help me.

I've just bought a new computer with Win 7 Pro 64-bit installed. I have the OEM disk (64-bit).

I now find that W-7/Vista 64-bit drivers are not available for some of my hardware (in particular my Dell 2405FPW monitor and Philips Voip321 Dualphone). I want to "downgrade" to the 32-bit version.

I have a 32-bit disk available (OEM) and if I understand correctly from reading other posts my 64-bit Licence Key# can be used for either version. Is this correct?

My next question: can I install the 32-bit version "over" the 64-bit version or do I have to do another clean install and re-install all my other software, documents etc.?

One more question: if I change my mind again, and want to revert to the 64-bit version, can I reverse the process ... i.e. install the 64-bit version over the 32-bit version?

I'll be grateful for some expert advice.

Simply, no. Clean install on each instance. Lose all settings and software installed each time. License good for both as I understand it.

You will need to do a clean install or custom install.

as far as an OEM key working for both versions, I'm not sure. My guess is probably so.

MUff1N said:

Just install the 32 bit drivers for what needs it & keep the 64 bit OS installed!

64-bit OS needs 64-bit drivers.

Correct me if I am wrong, but I believe once you have validated your genuine copy over the internet with MS, you will no longer be able to deinstall one bit version in order to reinstall the other bit version.

Dans said:

Correct me if I am wrong, but I believe once you have validated your genuine copy over the internet with MS, you will no longer be able to deinstall one bit version in order to reinstall the other bit version.

you can do it so long as you only use one version at a time. If you have any problems activating just call up Microsoft and explain the situation (activate by telephone).

Thank you all for your input. Not the answer I was hoping for, but that's life. I'm going to bite the bullet and clean install the 32-bit version.