Installing next edition of XP on hard drive will permit to switch between OS with nothing extra but just reboot. This allows protecting data, having backup copy of OS if anything goes wrong with first installation. To achieve this, you want to make two partitions on hard drive. This will trick PC into thinking you have one or more physical hard drive, permitting you to install many copies of Windows XP.

Instructions

Step 1

Put in Windows XP disk and restart system.

Step 2

Press any key to walking boot from disk as PC is loading.

Step 3

Push "Enter" to start installation and "F8" to agree to licensing agreement.

Step 4

Press "D" at partition manager screen to delete current partition. Press "C" to make new partition. Make two partitions of equivalent size, one for every installation of XP.

Step 5

Choose initial separation and format it by NTFS file system. This install initial copy of window to hard drive.

Step 6

Do again whole procedure; apart from choose second partition and formatting it by NTFS file system. This installs second copy of Windows XP.