The latest Apple Macintosh (Macs) run on Intel processors and have the ability to run Windows natively as well as running them in Virtual sessions under Mac OSX. Apple have provided a tool called Bootcamp that allows the installation of Windows onto a Mac but there can be a few problems to overcome to ensure a successful installation.
The installation of Windows can be done at any time as long as you have enough disk space available - for Windows 7 you will need at least 12 GB for the install but it is recommended to have at least 50 GB set aside to host Windows.
You can also install older versions of Windows (such as XP, Vista) and then upgrade them to the latest Windows 7. This can be useful if you already have a fully licensed copy of Windows XP or Vista and just wish to purchase an upgrade license for Windows 7 which is much cheaper. There are though some considerations for doing a WIndows XP upgrade - you cannot do an in-place upgrade and so must back up any data and then you must do a Custom upgrade that will essentially do a new install whilst saving your existing license information.
It can be useful to have a USB keyboard and mouse as sometimes the install can have problems recognising the wireless keyboard & mouse when first installing.
Always backup your Mac before installing - you never know you may accidentally delete your Mac OSX partition or have some other issue.
If upgrading from Windows XP you will need to ensure you have at least installed Windows XP with SP2 (preferably SP3) through Bootcamp first. You cannot install Windows XP with SP1 and then upgrade that to SP2 or SP3 - it must be a clean SP2/SP3 install. You can create an SP2/SP3 boot & install disk - just check the web for how to do this and burn a copy onto a blank CD and then install this.
You can begin the Windows installation by starting the Bootcamp Assistant that can be found in the Utilities folder in Applications on your Mac. It is best to choose the option that you have the Mac OSX Install DVD available (as long as you have it) rather than download from the Internet and then you are next prompted to choose a partition size for Windows. As mentioned choose a good size (50GB) and then you will be asked to Start Installation by inserting the WIndows Install CD/DVD and rebooting.
The Windows install should proceed as per a normal Windows install on any other machine - but check carefully that you are installing Windows to the right disk partition (should be labelled BOOTCAMP on your screen when prompted to select the disk). There are instances when doing a Windows 7 install when part way through you may just get a black screen although the Mac is still powered. This is caused by a video driver problem preventing the screen from showing. If this happens you will need to power of the Mac and restart it and press any key when prompted to start the Windows 7 install again. It should recognise a part installed Windows and you should select boot to safe mode with Command prompt and delete a file as follows:
At the Command Prompt, type DEL C:WINDOWSSYSTEM32DRIVERSATIKMDAG.SYS to delete the default ATI driver, then close the window and reboot.
The install should now be able to proceed again and once installed you should immediately install the Windows updates, Anti-virus (AVG is a good free-one) and also the Apple Bootcamp for Windows drivers and utilities. These can be found on the Mac OSX Install disk - just pop it when running Windows and run setup.exe (it may autoboot). It will ensure you get the right drivers to support the Mac hardware. Also ensure you install the Apple Update tool - there is a large update for Apple Bootcamp for Windows that should be installed immediately as well.
If you installed Windows XP then you will need the Apple Bootcamp drivers to run your wireless keyboard and mouse as well as get the right video driver.
If you are then going to upgrade from Windows XP to Windows 7 then you can now insert the Windows 7 DVD and run the upgrade. As mentioned it is a Custom Install that will totally wipe the XP copy and all data so you should back up anything you may have stored on the XP partition. A quick way to do this is to actually clone the Windows partition running a tool called Winclone for Mac. This is run under Mac OSX and takes an image of the Windows partition and saves it under Mac OSX. You can then go back into Windows and run the Windows 7 Custom Install.
There are instances where the Custom Install cannot start (such as if you are going to create a 64-bit Windows 7 install) over a 32-bit Windows XP. In this case you can opt to just run a clean Windows 7 install and when prompted to enter the activation key skip this part and come back to it later when Windows is installed. After installation re-insert the Windows 7 disk and run the install again - and choose Upgrade. After this Upgrade runs you can then enter your License/Activation key information. This has been checked by Microsoft as a legitimate way to use the Windows 7 upgrade disk.
If at any time you run short of disk space on your Windows partition then you can again use Winclone to clone your partition in Mac OSX, delete the old partition using Bootcamp Assistant, create an new partition of a larger size and then use Winclone to place the old Windows image onto the new re-sized partition. You may get some disk errors on startup but allow CHKDSK to run and all should be fine.
Once installed you can change the boot sequence a number of ways so that either Mac or Windows is the preferred boot OS. In Windows, if you installed the Apple Boot Camp tools you will have a small grey square/diamond on your bottom right hand system tools bar. Right click this and open the Boot Camp Control Panel. In there you can change the boot OS. Alternatively when starting the Mac press the right hand ALT key (called Option in Mac) and you will then be shown Mac OSX and Windows as boot disks - just select the one you wish. In Mac OSX you can go into the Disk Utility and from there again select the Startup disk.
Note that you cannot easily transfer data between the two OS partitions - unless you installed Windows XP as FAT32 formatted disk which is only supportable for partitions under 32GB. For most of us running Windows Vista 7 we will be running NTFS disks and so you need to move data using CD/DVD or USB sticks. Or you could email it to yourself .
Now you can enjoy native Windows on your Mac for all those applications that still haven't entered the world of Mac !!