Defragment System

Hi everyone,
I have a problem when i try to degramenting my system. After the system degramented to about 6%, it stop and gave me a message said that there were some files that cant be defragmented. here is what the log said

Fragments: 2,645
File Size: 21 MB
Files that cannot be defragmented: \System Volume Information\_restore{D22B3738-F4D2-4A69-A71C-12DD5A7303D2}\RP59\snapshot\_REGISTRY_MACHINE_SOFTWARE

Can someone tell me how i cant delete this file or what is this file. I have total of 3 drive in my computer and i cant defragment none of the drive. Really appreciated for the help and thanx for the help.