files wont defrag-keep appearing after a restart and analysis

the same files on my C drive after a defrag keep showing up after restarting and analysing. they are only 5 to 8 files, and add up to 10mb in total. I say 5 to 8 as the number keeps changing. Most of the files are temporary and in system32, one is a typical wallpaper jpg from the picture folder, another is a stylexp installation file. My other drives (D, a partition of C, and E a seperate drive), have no issues with defraggler, it works fine with them. After a restart and analysis it tells me i have no fragged files with these drives, unlike drive C which has the same files showing up. Does anyone have an idea as to why they keep showing after i defrag these files? I have checked the system and have no noticeable drive errors. On a drive with temp files and windows installed, will i always have files needing a defrag even straight after using defraggler and restarting?

thanks for any info if possible