Few Steps to be followed to Install Windows 7 using USB drive
1. Format the Pendrive using NTFS Format.
2. Open start menu and right click on run command and select "Run as administrator".
3. Now type following commands (without quotes) and hit enter key after each command.
4. "diskpart" - This is used to open disk partition manager.
5. "List disk" - This command will show available drives on your system.
6. There will be displaying a list of disks. Note down the label it will be some integer value of the pendrive.
7. "Select Disk X" where X is label of the pendrive that to be noted from the previous step.
9. "Create Partition Primary".
10. "Select Partition X". (Assuming the pendrive is 1) This command is used to select the pendrive.
11. "ACTIVE" – is to activate the pendrive.
12. "Format FS=NTFS".
14. "EXIT" - Disk partition program is completed and it will exit.
15. Insert the Window 7 installation disk on the DVD drive. Now type following commands.
16. "G: CD BOOT" - Assume DVD drive as G and pendrive as H.
17. "BOOTSECT.EXE/NT60 H:" - to update the pendrive with bootmgr code.
18. Copy contents of Window 7 DVD to the pendrive without any error.
19. Insert pendrive in the system.
20. Now pendrive is ready to install Window 7 to the system, but there should make some changes.
21. Change the boot order and select the pendrive as a first boot device.
22. Assign highest priority to USB Drive by assigning first place to it.
23. Save settings and restart the system.