Before doing any installation restart OSX from your 10.6 Snow Leopard DVD and use Disk Utility to Both Repair The Disk and Repair the Permissions of your Macintosh HD.
Next remove your Snow Leopard DVD and restart your iMac into OSX.
Update to the latest version of OS X Snow Leopard by clicking the Apple icon and choose Software Update to install Snow Leopard v10.6.8, the latest version.
Use Time Machine to make a Full Backup of your Macintosh HD.
Shut down and restart into Windows by holding the Option key at the chime and selecting Windows.
Now use Windows Backup to make a Full Image Backup of your Windows Installation to a removable drive.
Shut Down and Boot back into OSX.
Open the Mac App Store from your Dock to buy and download Mountain Lion. Then follow the onscreen instructions to install it.
Upgrading your OSX to 10.8 should not effect the Windows Partition at all since you are only upgrading the Mac side. You should not have to run the Boot Camp Assitant 5 Utility in OSX at all.
Your Boot Camp 3.3 Windows Support Drivers et. al only effect your Windows installation and should continue to run fine after upgrading.
Which version of Windows do you already have installed on the existing Boot Camp Partition?
Is it 32 bit or 64 bit?
Thank you for the suggestions on getting a clean system prior to updating.
My windows partition is Win 7 Ultimate 64bit.
If I wanted to update to boot camp 5 to get the latest drivers, bug fixes, and firmware updates, do I have to delete the existing bootcamp 3.3 windows partition and reinstall OR can i just run boot camp 5 assistant and keep the old partition without reinstall of windows?
You can do the 10.8 upgrade which will leave your Windows 7 partition intact.
The only downside is that OSX 10.8 upgrade will not install the Recovery Partition.
In order to create the Recovery Partition OSX 10.8 would have to reformat the existing hard drive and would corrupt/wipe your existing Boot Camp Windows partition.
However just doing an upgrade of OSX 10.6 will not reformat the Hard Drive and No Recovery Partition will be created.
But on the bright side OSX 10.8 Internet Recovery is accessible if ever needed.
You can also search on how to create an OSX 10.8 installation removable hard drive or DVD. I believe the newest Carbon Copy Cloner has a feature to do this but I am not absolutely certain.
You don't have to bother with the bootcamp program stuff and can just download the zip file
http://support.apple.com/kb/DL1638 from within your Windows 7 x64 side.
Just download and save the Boot Camp 5 Windows Support Software on the Windows Desktop, unzip the file, run setup, and all the latest Boot Camp 5 drivers and components will be installed before you even begin your upgrade to OSX 10.8 on the Mac side.
BACKUP, BACKUP, BACKUP.
Thanks rtheb! I will try the boot camp 5 driver update prior to my upgrade to mountain lion! I didn't know you could do that.
I appreciate your insight on the recovery partition. I am concerned that I would not have a recovery disk but I have paragon HDM and can use that to generate a recovery disk.
I would like to run windows ultimate 64bit off of an external SSD hard drive if that is possible. Do you know if that is possible on my late 2010 IMAC? Can you refer me to a link?