Cyanotical

Often people turn to online tools, and they never quite work right for windows, however, the tools for making a boot-able USB drive are build into all versions of Windows since Vista and 2K8:
Standard Installer (Vista/7/8/Server):
first, insert your windows vista/7/8/server disk or mount the iso, as well as the USB dive you will be using, take note of the assigned drive letters.
in this case i'll be using L: for the DVD drive, and M: for the USB drive

next, right click the USB drive and select 'Format':

select 'NTFS' as the file system, name the drive, and click format:

next, open an elevated command prompt or powershell (right click and 'run as administrator')
navigate to the DVD/ISO boot folder by typing cd x:\boot ('x' is the letter of the DVD drive or ISO)

next, type bootsect /nt60 y: ('y' is the letter of your USB drive you just formatted)

next, simply go to your DVD/ISO and copy all the files, then paste them into your USB drive

and that's it, you're done, no looking through 10 websites for a boot tool, or risking viruses, malware, or whatever
one thing to note, this only works for Windows, if you want to use Linux, are currently using Linux, or simply want a tool anyway, get Unetbootin
also, if you want to make a universal Win7 installer, (you can pick which version you want to install, such as home or pro, but not x86 or x64)
in your win7 ISO, or USB drive, go to :/sources/ and delete the file named ei.cfg

UEFI Installer (8/Server 2012):
this is for the most part a CLI drive management partitioning and then a simple copy/paste
first open a elevated command prompt or powershell (right click, 'run as administrator'):
type diskpart:

next type list disk:

now, look for the USB drive you are using, it is very important that you select the right one (judge by capacity, they don't make 8GB hard drives anymore)
in this case my USB drive is disk 7
type select disk x ('x' is the number of your disk)

now type clean (this will erase any data on the disk)

now type create partition primary:

next type active:

now type format fs fat32 quick:

now type assign (this will cause the explorer to pop up with the drive)

go back to the command line and type exit, then go to your Win8/Server2k12 DVD/ISO, select all the files, and copy them

now just paste them into the USB drive:

that's it, no bootsect or boot partitioning needed, it's possible to do this through Disk Management, but CLI is a bit faster and linear
all you have to do next is plug the drive into the computer, the USB drive should be detected as a UEFI option
as for the actual install, not every EFI motherboard is ready for an actual UEFI install, some may just not work (cough*rampage IV extreme)