This is probably the easiest way to switch over(or atleast give a try) to Linux.

Ubuntu gives a special option to install ubuntu inside windows. All you require is a cd/image of the same and atleast 5Gb free space to install.It makes a dual boot system and does not harm the windows installation

No partitioning is required and there is absolutely no compromise on the performance of both the operating systems(ubuntu/windows)

Here is how its done:

Step 1. Insert the ubuntu   CD (live) or mount its image with daemon tools(or any other virtual disk program).I used  an image of ubuntu 8.10 . Ubuntu Cd can be got free of cost via mail or downloaded from ubuntu.com

It gives the following options.Choose Install inside windows

step 2:

Choose th e drive in which you want to install the OS and the amount of space you want to dedicate(anyhing above 7 to 10 Gb is good enough).No need to partition,Just choose any of the NTFS/FAT filesystems.

Also write the username and password you want for ubuntu installation.

Step 3:

Click install and the installation starts.Reboot the system when over.

Reboot the system into ubuntu to finish the installation.Use the username and password entered in step2.You are now ready to use the most rocking OS ever made.