BootCamp Update 3.2. .exe file, Windows 7 uninstallable with cordless mouse until drivers in. What next then?

Question

Trying to get windows 7 to run under iMac. I am learning to fly and the best flight simulator (I'm told) is still FSX which does not run on the iMac which I made my main computer infrastructure last year.  And besides it's got the best screen in the house.  Before buying both a virgin copy of Windows 7 (expensive) and of FSX (ditto) I checked the forums and there are definitely people saying it works.
My iMac has a cordless mouse and a cordless keyboard.  I have read that the latest software which makes these work is in BootCamp3.2. 
I quote from the apple pdf on installing windows:
Step 1 : Check for updates.  In Mac OS X go to http://www.apple.com/support/bootcamp and check whether you need to update your software before you can install windows. 
Yes I do.  Can't call that URL very helpful on file selection, but OK, I worked it out.  (Though could someone tell me if ALL intervening updates need to be applied.  I had no way of telling where the full set of updates was, so I had to assume installing the latest would work.)
OK - so I need to install BootCamp_3.2_64-bit.exe
But having downloaded it, if I run it it opens in a text editor.  Why is that?  Explanation will help.  But why is there nothing at Apple on this?  It's apple software. 
Searching I found people sounding equally confused, and someone says you'll need to burn it to a disc.  That took a fair while too - but I did it.  I found the help on burning very poor.  It's hard to find how to put a file on a disk.  The defaults are all for music and films. (Tip - use Finder, not other options, when you put a blank disk in)
So I now have the bootcamp upgrade file on a DVD.  I learn (slowly) that because it is a .exe it must be run from Windows.  But I have not got windows, that is what I am trying to load.  And when I load the Windows Disc I can't get very far, because it can't cope with a cordless mouse, until the drivers are upgraded.
I am now worried that things will get worse, because the rest of the forums say you can't make Boot Camp Assistant work when there's already a partition made.  And, there is.  I made one before being trapped by a driverless cordless mouse.
I have an iMac 2.93 Ghz Intel Core i7.  8Gb 1333 MHz DDR3.  ATI Radeon HD 5750.  A cordless mouse and keyboard.  I Bought Windows 7 Home edition 64 bit.    
I'm a bit disillusioned.  I bought this hyper computer to run some number crunching simulations via an Oracle database.  The setting up was 10 - 20 times more difficult than setting up Oracle on my Dell laptop.  The simulations ran half as fast as on the laptop and appeared to be frying the iMac's own hard drive.  So I stopped.  I flirted with Times Ten - but it was unsuited to my codebase (not Apple's fault) and then gave up.  So this lovely computer is now used by my daughter to watch movies.
This is the second attempt at doing something moderately serious, and both have been very disappointing.  If you think it's worth saving someone who is about to give up on Apple completely and leave this powerhouse to an idle life of Facebook, then your assistance will be sincerely appreciated.  It's been 6 hours, a very irritating six hours, so far.

Answer 1

You really really do need to read the Windows 7 FAQ the Boot Camp 3.0 Installation and Setup guide for 10.6  and the Boot Camp 3.0 MacOS 10.6 FAQ  a couple of times to really get to know the whole picture.
"Boot Camp" is just a basic set of WINDOWS drivers to run Apple hardware. You install Window first, via BCAssistant to start it, then after it finish's the install and restarts into Windows then you insert the "whatever you made disk" with the Boot Camp drivers on it, it should then give you an installer window, just like on the Mac side, if you want to "Run" it or "Open as a file". (Run it)
The Apple Software Updater updates ALL the Apple files including BootCamp Assistant on the Mac, it updates the Boot Camp Assistant to look for the latest drivers to use when it gives you the option to download the files onto whatever you want to use to download onto.
BTAssistant to partition the drive, then it will boot off the Windows installer, there is no more Mac control, it's ALL Windows now, have Windows format it the way you want, then it will finish by restarting into Windows, then you install the drivers while booted in Windows.
You need a wired mouse AND keyboard just like the instructions said. If you have the earlier Magic Mouse then they suggest you plug it into the keyboard instead of the computer.
If you partitioned like the instructions said, via Boot Camp Assistant, you can install Windows anytime you want, it won't forget it's there. YOU just have to remember where it is.
If you do have problems with the partition then at the bottom of the instructions it tells you how to restore the partition back to normal then you can start over.