Hey PK, and others
Yeah, the PF is used by the OS. If you have tons of ram, you can even turn it off, to stop the HDD thrashing at times. These days though, with large fast hard drives, it's better to just leave it on, and let windows handle it, plus a couple programs (like Photoshop) whine if they don't find a PF. Windows will only put the PF on the system drive and I wouldn't move it.
Years ago, on slower computers, I used to split my drives in three: one for the system, one for data, and one for temp files. I also made a folder "zzz-temp" as that would put all the temp files on the edge of drive which was the fastest part, and resized the PF to 4x my ram, and put it in the folder. These days, it's unnecessary.
I'm tempted to get a SSD for my system, though, but they're still too expensive (I would want a minimum of 128GB for the system drive).