If you don't know anything about DOS commands then you will have to learn them, this is not a DOS tutorial.
Here are the steps you have to follow to create a bootable Win7 installation USB drive:
1) Load cmd.exe and make sure you have chosen "Run as Administrator"
2) You should be under c:\Windows\system32, if not then you have to change to this directory. Type in â€œdiskpartâ€ in the command line to enter the Disk Partition command line tool.
Next, type the following commands, one at a time:
3) Type â€œlist diskâ€ to reveal a list of all your active disks. Make a note of the number associated with your USB drive
4) Select Disk # (where # is the number associated with your USB drive)
5) Clean (removes any existing partitions from the USB disk, including any hidden sectors)
6) Create Partition Primary (Creates a new primary partition with default parameters)
7) Select Partition 1 (Focus on the newly created partition)
8) Active (Sets the in-focus partition to active)
9) Format FS=NTFS (Formats the partition with the NTFS file system)
10) Assign (Gives the USB drive a Windows volume and next available drive letter)
11) Exit (Quits the DiskPart tool)
12) If you have an ISO of the windows installation DVD then extract the files to a folder on your hard drive (using WinRAR for instance)
13) Change directory to either the installation DVD or the folder that you extracted the ISO files to.
14) Change directory to the directory called "Boot".
15) Now type in "Bootsect.exe /nt60 L:" (where "L" is the drive letter assigned to your USB key from the previous step)
16) Copy all the files from the installation DVD or the extracted files from the ISO over to the USB drive.
That's it, you are done.