How to force LAN share from external drives not present at boot?

My problem is that I've long shared certain PC internal directories with other LAN PC's (XP and 7) and it works great. However, I needed more space and have just moved several of those directories to external storage (NexStar HX4 w/ USB 3.0 connection) and it appears to be working fine except for one gotcha.

Given the nature of those shared directories (media files), I often use the PC w/o any need of accessing them and so the external drives can be left shut down during Win7 Ultimate 64 bit boot. The problem is it appears that if Win7 doesn't see the shared directories at boot, then their sharing is canceled. That is, if I bring up the external drives after boot, sharing does not take place. However, if the drives are powered before boot, they are shared as desired, and I can even power them down and later bring them back online, and sharing survives.

Since Win7 is obviously able to preserve share declarations during post boot power down of the external drives (it doesn't cancel them, it suspends them until the drives return), surely there's a way to force that identical behavior if the drives are down at boot? Sure hope so anyway, this seems kind of Mickey Mouse the way it is!


Noob Whisperer
Hello and welcome to the forum.
Could be that your USB devices / ports are being caught up in some power management settings.
Check them all and see that they are not... see attachment
USB_PwrMgt.png USB_PwrMgt2.png

Thanks for taking a look!

I'm actually using a SYBA dual port expansion card (SD-PEX20139 w/ Renesas driver). I checked the properties of both root hub and port controller and only the controller had a switch -- "Disable USB 3.0 power management functions". It was defaulted to clear so I tried checking it but no difference in boot behavior (now clear again). The mainboard (Asrock 980DE3/U3S3) has a native dual USB 3.0 port controller (Etron driver), but it's properties don't include any switches. I've tried both sets of ports, but the behavior is the same.

Just realized I didn't explain the behavior properly. If the PC is booted without the external drives and they are then powered, then the drives won't be shared, but the settings are apparently not discarded, they're just not applied. Shutting down the drives again and bringing them back doesn't change that. But, rebooting with the drives powered causes them again to be shared. Also, I was thinking that when the external drives are shutdown, they ceased to be "shared", but that's wrong, though if a LAN PC tries to access them, there will be an availability error. So, I guess what it comes down to is the "drive status subsystem" doesn't alert the "sharing subsystem" when a drive either comes on or off line, and so the broadcast sharing status never changes following boot. So, there would appear to be only one status update and that's at boot -- darn! Guess Microsoft never took external drives very seriously, seems to me they've been available for well over ten years!


Noob Whisperer
Test again only this time with a simple log off and then log back on and see if it has something to do with the way the netBIOS share are propagating. If they show up after you log back on (without the reboot) then it apparently has something to do with an unknown period of time before the browse master is updated with the newly available network resources. If they don't show up then it's back to some hardware issue with power available to the port which is generally determined at boot during device enumeration.

I think a hardware issue has next to zero likelihood. Windows Explorer is fully aware of when the external drives are powered and functioning Vs when they're not. The drives/directories/files are either displayed onscreen, or they're not. What's missing is a logical connection between sharing and post-boot drive availability (mounted Vs dismounted). That's a system level software problem -- I was hoping there might be a software parameter/switch that closes that gap!

I don't normally use logon/off since I'm the only user, but I'll try it to see if it influences sharing, guess it could since sharing could potentially be user specific and could trigger a drive status query. Thanks for the thought!


OK, so with the external drives powered down I rebooted, then powered the drives and verified they were not shared on the LAN. I then logged off and rechecked share status, the drives were still not shared. I finally logged back on and again rechecked share status, they still were not shared! In other words, the drives are either powered at boot or they won't be shared (I've seen no evidence of delayed action). Would Microsoft consider this a defect, feature, or enhancement request?

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