You might not be able to make Windows perform like a Mac but you can definitely make it look and feel like one with some free tools you can install in minutes. Checkout the following tips, tricks and tools and enjoy your new Mac-lite PC.
Rainlender is a skinable desktop calendar
Trillian is a universal instant messenger that resembles iChat.
iTunes is most likely already on everyone’s system but just in case, here ya go!
Change your desktop wallpaper to one that the Mac Leopard OS uses. Search google for other images if you don’t like this one.
Change your mouse cursors to Mac OS X cursors
Apple icons are a must have to put the finishing touch on your pseudo-Leopard OS.
Here are over 1,400 icons.
Replace your Internet Explorer browser with either Safari or Firefox (if not already!).
Replace Microsoft’s Gadgets with Yahoo’s Widgets which look and feel more Mac-like.
RocketDock will probably give your PC the most Mac-like appearance and functionality because it replaces the windows taskbar and allows you to launch all of your applications from its very Leopard-style interface. Here’s a good video of how it works:
ObjectDock is similar to RocketDock. Give them both a try to see which one you like better.
Here’s another screencast:
Note: It doesn’t make sense to have RocketDock or ObjectDock and the Windows taskbar visible at the same time so it’s best to hide the taskbar. Right click a blank space in ObjectDock, go to the settings tab, select behavior then on the box with check marks select “Hide the Windows Taskbar”, and hit OK.
Installation Kit
For Windows XP users, you can try FlyakiteOSX which is a free installation kit that does most of the dirty work for you. I’m not sure it will work with Vista so I cannot vouch for it! Let me know if you get it to work though. 
Final Thoughts
Yes, I know it’s a lot of work, isn’t it? Why not just get a Mac if you’re willing to go to all this trouble to make your PC look like one? Well, I actually happen to love how my Vista looks and performs and merely offered this up for those that want the Mac look n’ feel but for whatever reason are stuck with a PC (being in IT, I hold many MacHeads captive to the Windows OS because of corporate policy). Maybe I’ve done this out of guilt for keeping these Apple lovers away from their beloved OS.
