Defraggler is a program to defrag your entire hard drive, or individual files. It supports NTFS and FAT32 file systems.
There is a free version. Download it from here. Defraggler needs administrative rights to defrag an entire hard drive in Windows 7.
You can replace your default Windows 7 defragment tool with defraggler if you are not satisfied with the default one. Defraggler asks you during installation if you would like to replace it.