Using VM(Parallels 8) On An iMac

Boot Camp allows you to install Windows on a volume. You don't need to use it. Just open the virtual machine app, create a virtual machine and install Windows. The process to install applications is the same as on a computer. If you want to install applications from a disc, you will have to mount it into the virtual machine. To do it, you should see a bar in the virtual machine window where you will be able to mount it.

You need an antivirus for Windows. You can search in Internet for one. When I used Windows, Avast was my antivirus and I haven't had any issue

Just a few observations:

Your early 2008 iMac will be sloooow. Running Parrallels 8 will need as much memory as possible (8GB minimum) for speed.

The Windows VM will require ~30-40GB of disk space. You should still have ~20% of your Harddisk space free otherwise the iMac slows down.

First of all, start the virtual machine. If you have a look at the bottom right part of the virtual machine window, you will see some icons, so press the USB icon and choose your external disk, so it will be mounted into your virtual machine. Note that you may have to install Parallels Tools in the virtual machine.

Then, you can install the apps as you would do on a computer with Windows. Open Windows Explorer, open your external disk and install the apps

Goto http://www.parallels.com/products/desktop/

select tutorials (bottom half of page)

Then Select "Getting Started with Parallels Desktop"