How do i install 7 without booting from disc ?

Hey guys , I have a computer Running XP and when i try and install windows 7 it gives me the following :

Windows was unable to create a required installation folder , Please Reconfigure your boot.wim file to use the Flag 9 settings for the first image, and restart your installation.

Error Code: 0x8030002F.

My Computer Wont boot from the Disc on any of my Drives. Is there a way to get round this or bypass this or somthing to download to help ?

Any help would be Great! I Have another computer with 7 on , but that was installed by booting from the disc. Thanks