I try to defra my drive C: but there is a C:\system volume information\ that is unable to defra which take up lot of the space Pls help
the attachment is the file the i unable to defra

Think thats "rollback file" I just ignor it, any time with the last version of defraggler it caused defraggler to fail then I deselect it. On my Vista there are two others files defraggler can't defrag and also a c:\ image file i have on seagate external drive defraggler can't do that either.
If defraggler failed i been re-analyze until till I found the cause by looking through list for system volume and also the system32 file that couldn't do and deselect that files. The later version seems to complete defrag ok and just leaves the three can't.
I use defraggler pretty much every day and it keeps Vista running smoothly, big well done I think. Plum

I say there is no need at all to be concerned about System Volume Information not defragmenting.

System Restore data is stored here and is constantly being written to. One could go mad and insane trying to keep it defragmented because as soon as defragmenting is complete, it can become fragmented almost instantly.

System Volume Information can absolutely make this folder heavy, especially if your system has been in use for some time. Advanced Windows users concerned about disk space could manually delete Restore Points or turn off System Restore.