I have an old Toshiba that has no optical drive. To install Win7, I needed a bootable USB stick. Here are the basic steps
0. Download Win7 http://www.microsoft.com/windows/windows-7/
1. Get a USB stick – need a 4 gig one here – the ISO is about 2.5 GIG
2. Format the USB as NTFS (use quick – no need for sector check) – it MUST be NTFS
3. Run DISKPART from an elevated command prompt
4. Make the new USB volume “ACTIVE”
5. Extract the Win7 ISO somewhere (not the USB) – you can use ImgBurn, IsoBuster, WinRar or some tool that can extract direct from an ISO – or mount with Daemon tools or similar, then copy the files from there. We need to extract first as we’ll need to run a quick program off of the Win7 ISO
6. On the recent Win7 extract, change to the BOOT subdirectory
7. Run BOOTSECT /NT60 <targetDrive:>
where , <targetDrive> is the drive the USB stick is mounted as….
8. Copy all the files from step 5 above to the ROOT of the USB stick (with subdirectories of course)
Now, you may be able to skip step 5 copying files across and running BOOTSECT directly – I hadn’t but doesn’t necessarily mean it won’t work.