Ah awesome Problem. Yesterday I came to Hyderabad to meet my friends here. In some free time, we tried to install Ubuntu on Abhishek's machine. Machine already got Vista so doubt was very high from my side for installation. And again, machine is AMD64. Anyway, first I tried to install from from Hard Disk. We are looking for Ubuntu 8.04 installation which you can do inside windows and the installation is awesome. Uninstallation is like do in Add/Remove Program in Windows, you will get a application with name Ubuntu, click Uninstall and that's it.
Anyway, installation directly was unsuccessful. Then we tried to make the ISO file and then tried to installation. But here goes something funny. CD size was 702 MB and the ISO file is 698 MB, so not a big deal. Before opening the CD, Vista do formatting of CD and after formatting it makes it 692 MB. OMG !!! what is this. And I for testing purpose ran the formatting again and size of CD went to 683 MB ! What the heck. Our final conclusion if we keep on formatting a CD on vista, size can go to zero :-). Still we have not installed Ubuntu on Vista, will keep on updating the problems.