I had written the tutorials to make a Pendrive / USB drive bootable for installing Windows Vista and Windows 7 from it. But the steps given in those tutorials worked for users using Windows Vista and Windows 7 only. So some of my visitors asked me for a solution since they were using Windows XP. (Thanks Miguel for bringing this to my notice).So Here is it.
First you have to format your pendrive / USB drive to NTFS format.
For that download this tool and format your pendrive in NTFS format. Don’t use quick format option. Now follow the steps from step 14 on this tutorial to Install Windows 7 from Pendrive (Work for Windows Vista Too).