My computer annoyingly swaps something to disk once per second. The concern is strained by the fact that the Filemon shows no file activity! Another Sysinternal's utility, Diskmon, does show that the OS driver flushes some sectors on the disk. Who writes which file? The "sector to file" mapping is needed.
I have discovered the DiskView utility that builds the map of file locations on the disk in sector clusters. The conversion between sector and cluster can be done by the "fsutil fsinfo ntfsinfo c:" command. This forum was helpful. Expectedly, the swapping accessed the system sector meaning it is performed by the OS.