Sit back, and enjoy :P

Windows 1.0 :

http://www.youtube.com/watch?v=GL4hyATkQ74

Windows 386 :

http://www.youtube.com/watch?v=B-rGzIOEIJE&eurl=

Windows 95 :

http://www.youtube.com/watch?v=30BWTIoXwPk

http://www.youtube.com/watch?v=5VPFKnBYOSI

Windows 98 :

http://www.youtube.com/watch?v=QYTQR5r2j3Y

Windows XP :

http://www.youtube.com/watch?v=4A_Kkb9w5bw

Windows Vista :

http://www.youtube.com/watch?v=YGBHUldWyHw