How to Dual Boot XP Windows 7

Partition your Windows XP Hard Drive
1. Click 'Start,' then click 'Control Panel.' Click 'Performance and Maintenance,' click 'Administrative Tools' and then open 'Computer Management.' Click 'Storage' then open 'Disk Management (local).'
2. Right-click on the drive that you want to install Windows 7 on, and click 'Shrink Volume.' In the 'Shrink Volume' window, ensure you enter over 16384MB to shrink, as this is the minimum amount of space required to install Windows 7. Hit OK to perform the shrink.
3. Right-click the new 'unallocated space' created by the shrink and click 'New Simple Volume.' Remember the name of the new volume you have created.
Installing Windows 7
4. Insert your Windows 7 installation disk and restart your computer. It will automatically start the installation wizard on startup.
5. Follow the easy instructions on the Windows 7 installation; however, when asked, 'What type of installation do you want?' select 'Custom (advanced)' and change the partition so it matches the name of the one you just created. Continue with the installation process as normal.
6. Restart your computer, and at startup you will be given the option of running either Windows XP or Windows 7.