Hi, I have a NAS at home and have it mapped as Z: and Y: drive. Everything is okay when I'm at home when the drive is accessible. However, when I'm in some other place where the network drive is not accessible, or even with wifi off on my laptop at home, if I grab a file with my right-button mouse and hover past the disconnected network drive (see the picture), Explorer seems to be searching for this drive if it is available or not, and causes a terrible stutter along with a ring making Explorer non-responsive for couple seconds and stutters the whole system. This is a huge annoyance because I have Y: and Z:, and it feels silly that I have to be careful to avoid hovering files over these icons inside Explorer. I have Windows x64, i5-2435m, 8GB ram, Samsung 256GB ssd. EDIT: This must be related to Kaspersky Antivirus 2012, because when I disable KAV2012 I no longer experience these terrible stutters. I opened a ticket with Kaspersky now.

Have you tried disabling file indexing on the share (or disable Windows Search altogether).

Hi, Also, check whether this still happen under Safe Mode with Networking. Juke Chou TechNet Community Support

This is weird. I'm not at home right now (away from NAS), and I rebooted into Safe mode with network support, and didn't see any stuttering now. Then I restarted my laptop to normal boot, and I'm not experiencing the stutter any more. If I try to open that drive, it stutters for couple seconds and says it can't access the drive. But hovering files over it doesn't make it stutter any more. I'll have to see if this problem was because I previously had NAS connection at home, then I put my laptop to standby.

Hi, OK, if you have any update, please let us know.Juke Chou TechNet Community Support

It looks like the cause is from Kaspersky antivirus 2012. I even tried disabling file scan, same problem. It only works okay when I disable KAV.