OK, after unsuccessfully trying all methods mentioned here, I finally got it working. Basically, the missing step was to write a proper boot sector to the usb stick, which can be done from linux with ms-sys. This works with the Win7 retail version.
Here is the complete rundown again:
Install ms-sys, if it is not in your repos get it here.
Check what device your usb media is asigned - here we will assume it is /dev/sdb. Delete all partitions, create a new one taking up all the space, set type to NTFS, and set it bootable:
# cfdisk /dev/sdb
Create NTFS filesystem:
# mkfs.ntfs -f /dev/sdb1
Mount iso and usb media:
# mount -o loop win7.iso /mnt/iso
# mount /dev/sdb1 /mnt/usb
Copy over all files:
# cp -r /mnt/iso/* /mnt/usb/
Write Windows 7 MBR on usb stick:
# ms-sys -7 /dev/sdb
...and you're done.
After all that, you probably want to back up your usb media for further installations and get rid of the iso... Just use dd: # dd if=/dev/sdb of=/win7.img and reverse if/of next time you want to put the Win7 installer onto usb.
Dit lukt me bijvoorbeeld ook NIET. Ik krijg geen toegang tot mijn USB zegt de terminal..
