How do I add /3gb to boot.ini in XP Home SP3 32-bit

right click My Computer and select Properties. Click the Advanced and choose Settings under Startup and Recovery. In the window that loads click Edit to add the /3GB switch manually.

How to Downgrade from Vista into XP

Use Fdisk to delete all the partitions.

Format the C:

In the Bios change Sata Controller Mode from AHCI into Compatability.

Install Windows XP