Windows 11 How to stop file expolorer from opening on boot

@Neemobeer Thank you for that suggestion. I did as you said but I can't see anything obvious in autoruns either. Checked the "logon" tab and the "scheduled tasks" tab. Tried searching for "iscsi", "D:", "steam" etc. But nothing obvious. Any suggestion what to look for?

Truthfully it could be anything. You can click the save button and export the results. You may want to do a replace on the output and replace your username with something like <redacted> before posting output.

Not sure if you're still looking for an answer on this, but I have a similar configuration (iSCSI share mounted from my NAS to my main desktop for storing games) and ran into a similar behaviour under Windows 10 (explorer window for the iSCSI drive often, but not always, opens on startup). I believe this happens because Windows can be set to automatically open drives when they mount, and depending on the exact timing of when the iSCSI drive mounts on first boot it can trigger this explorer window if the drive mounts slightly late after you're already at the desktop.

I went into the AutoPlay section of Settings and under "Choose AutoPlay defaults" I set both Removable drive and Memory card to "Take no action". I believe they were both previously set to "Open folder to view files" for me.

You wouldn't think an iSCSI volume would be considered either a memory card or removable drive, but I haven't seen the explorer pop-up on startup since making this change despite a bunch of reboots across a couple weeks. If you can find the equivalent page in the Settings app for Win11, you might have success changing these options. This likely means your PC won't pop open explorer automatically when inserting flash drives or other actually-removable media, but I honestly don't care too much about that and would much rather not get a nuisance pop-up on most boots if that's what it takes.