*** EDIT: Sorry, this is for installing from an external HDD, not internal HDD, I misunrestood Adem3311's question. ***
Hi Adem3311,
I installed Win7 from a 80gb external hard drive (because I had no 4gb usb drive at hand, only a 2gb one, and win7 install didnt fit to it).
What I had to do is to clean the hdd, but create a 4 or 8gig primary partition on it (because 80gb would be too big to be formatted to fat32).
1. Diskpart
2. List Disk
3. Select Disk 1 (Replace 1 with number reflecting your *external* HDD)
4. clean
5. create partition primary size=4000 (here you specify the size of the partition - 4gb)
6. active
7. format fs=fat32 quick
8. assign letter=x (where x is the drive letter you want to assign to the new partition)
9. copy all installation files from the installation media (in my case d:) to the newly created partition (x:)
One more thing what I had to do, is to update the bootsector to BOOTMGR by issuing the follwoing commands. Without this it didn't work for me (but as DChoung pointed out, this step may not be needed for USB drive, but apparently it was needed for the USB HDD, at least in my case):
10. d: (where d: is the original installation media, not the newly created)
11. cd boot
12. bootsect /nt60 x: (where x: is the newly created partition)
Be sure to issue the bootsect command (step 12) as administrator. It is important to issue this command from the installation media, not from the newly created partition (which also has the boot folder as we copied it from the installation media), because you'll get an access denied error then. If you get an access denied error anyway, make sure that you don't have an open explorer window with the new partition or any file operation pending. If this doesnt help, just remove (unplug) and plug the drive in again, and try again. I had a few tries until it completed the command successfully without the access denied error, but eventually it did.
After this, I could boot from the USB HDD, and install Win7 from it to my tabletpc, just as if it was a DVD or a USB flash drive.