VMWare is some pretty awesome software. Basically, it allows you to create virtual machines that run your OS of choice inside another OS. For instance, on a Windows XP machine I run a VMWare virtual instance of Ubuntu, allowing me to basically have two operating systems running at the same time on the same machine.

Now VMWare has released for free the VMware Player, which allows you to run OS images that others have created. to run linux under windows, Download the free VMWare Player, then download a pre-created image of Linux. (live cd)

How to login as Administrator in Windows XP?

The built-in Administrator account is hidden from Welcome Screen when a user account with Administrator privileges exists and enabled. In Windows XP Home Edition, you can login as built-in Administrator in Safe Mode only. For XP Professional, press CTRL + ALT + DEL twice at the Welcome Screen and input your Administrator password in the classic logon window that appears.

To have the Administrator account displayed in the Welcome Screen:

Click Start, Run and type Regedit.exe
Navigate to the following key:

HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows NT \ CurrentVersion \ Winlogon \ SpecialAccounts \ UserList

Use the File, Export option to backup the key
Create a new DWORD Value named Administrator
Double-click Administrator, and set 1 as its data
Exit the Registry Editor.