Bdtyktl

After installing 2 new HDD i saw Windows nonstop reading or writing to paths like 'L:1WindowsSystem32wbem' in the ressourcemonitor.
The disk is freshly formatted with NTFS and beside the automatically added $RECYCLE.BIN and 'System Volume Information' empty. So there should be nothing to read and in my opinion no access at all.

What i'm puzzled with is the strange path. What's the meaning of the number right after the partition identifier and before the backslash?

I'm using Windows 7. The access seem to happen to whatever partition has the highest character assigned and much free space.

Bonus question: How do i stop that? Those disks are supposed to be storage and should go to sleep if i'm not using them. Windows already has 2 SSD's to mistreat, why does it jump at new innocent HDD's?
As far as i know all temp directories are on C, pagefile is also assigned to C only, no automatic management of that. I even assigned a fixed ROOTDRIVE to the windows installer via registry editing.

edit1: after replacing the old disks, emptying them and swapping the assigned drive letters it still happens on the same disk. so the highest drive letter seem to be less important than size or amount of free space.

oh and since it is wanted to describe tried resolutions in addition to the plain question:
i tried searching for the problem on google and duckduckgo, but looking for things like 'windows' and 'path' there are just lots and lots of results about windows and the path variable in general. the same with drive letters.
also in the wikipedia article about path (computing) i did not found an example of a digit between the colon and the first delimiter.

i do have a guess. it may point to a specific entry in the file table, so the most likely target would be the 'System Volume Information' directory. I had a look at it using lubuntu but i found just a chkdsk logfile. Maybe the file explorer there does not show everything, maybe the files there get deleted on shutdown (i do not want to crash my windows on purpose, no other idea how to prevent that) or maybe they are just not there.

edit2: according to a Microsoft Doc about Paths it seems to be a relative path bound to a drive letter. makes sense but to my knowledge there were no directory '1' anywhere. Being relative trying to just use the same path in the explorer to go there is pretty much hopeless too. I tried and it just gives an error. "File not found, check your spelling and try again" (shortened and translated to english)

Oh and as an interesting addition i was unable to find that activity using Process Monitor from the sysinternals suite. The only hint that something is using the drives comes from the ressource monitor. In theory i could just look if the drive goes to sleep, but i don't know how to query that. Every status request using SMART tools or seachest (tool suite from seagate) wakes the disk and even causes them to move their heads. Only chance would be the 'listen and touch' test, but then there are 5 HDDs and 5 fans running, so slight vibration and noise is always there. Creating a clean test environment to check if a disk is really asleep would be cumbersome.