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Hidden Devices in Device Manager 1

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Accessdabbler

Technical User
Oct 15, 2002
728
CA
I've just been made aware of Hidden Devices in Device Manager.

Looking at the list, I see some devices listed that don't appear to be loading (the diamond is light-gray) and 1 device has a problem (Serial.sys).

1. How do I remove the devices that are not loading?

2. What is Serial.sys and how do I reinstall/fix it?

My machine appears to be working properly however I would like to know why Serial.sys shows a yellow exclamation point.
 
Im the "hidden device" guy :)
Most often, it's not a problem per se. It's just the way Windows 2000 and it's plug 'n play architecture works. Most often, though - it's that a serial port is not enabled in your BIOS. Windows 2000 doesn't care, or need the BIOS to do the serial port detection if using PnPOS set to "y" in the BIOS. It's one of those things you hear about, but don't see normally in Windows 2000. But - it's always there.

There are legitimate problems that can also cause it to not load. Serial.sys is a service that starts with Windows2000's Plug and Play service. You can check it's status there, but im leaning towards your BIOS not having all available com ports enabled as the cause. But that's okay on a Windows 2000 system. No need to dabble there :) pbxman
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I'll check my BIOS settings.

What do you mean by "Windows2000's Plug and Play service. You can check it's status there"? Where do I find Win2k's Plug and Play service? I looked in the Services and the Plug and Play Service is running, but there is no mention of Serial.sys.

p.s. I'm not sure I'd want to be known as a "hidden devices" guy.... [surprise]
 
hehehe..
Serial.sys is one of the Plug and Play system files that the Plug and Play service controls. They just rolled them all into one.

BTW - just gimme my leather mask, and don't ask questions..
bahahaha pbxman
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I too find the "hidden devices" list a mystery. Several of my devices have visible entries in the devices list and then multiple additional entries in the "hidden" list. For example my USB mouse has a couple of entries there. The record number of multiple entries is for a "generic device" which I think refers to the Zip discs that I use with my USB Zip drive.
Is there any detriment in leaving all these multiple entries? Is there any way of telling which of them are redundant? Is there any benefit in removing them?

Chris
 
The hidden list is based a lot on drivers, therfore a single device may have multiple drivers and thus multiple entries. As was previously noted, a lot of the "hidden" entries are for the PnP Service and not necessarily true and real devices. Also, I've noticed especially in Win2K that devices that are disconnected from USB ports get shadowed in the hidden device realm as well. I guess the thinking is that maybe, just maybe, sometime the device will get reconnected to that exact same USB port. And if the device is connected to a different USB port, then an additional shadow device is listed in the "hidden" device list.

All in all, most things in that list do not need any attention and should not be delete. Especially the gray diamond stuff which are primarily system drivers, stubs and kernel interface programs. The ones to watch for are for real but no longer attached devices. If you ever deleted an HP multifunction printer, for example, there may be some leftover there that can cause some problems.

Just remember, back up before you hack up. You don't want to disable your entire system with a swift click of the mouse.

PW
 
There's more to the fun still. The devices shown grey are old or unused connections, and non-plug and play devices most often. For instance, mine shows a MS PS/2 mouse with a yellow exclamation mark...which is fine because I now use an MS USB Optical mouse. It was once there, but isn't - yet the driver still remains.
There are still more devices hidden even when choosing to "show hidden devices". These are all the non-pnp devices that Windows hides from you. I also have devices (USB) that showup even though i haven't used them in a very long time. There's nothing wrong with leaving these..they are references to the drivers available when the device is plugged back in. Then, it will go from a hidden device to normal without the need to reinstall the driver.

to see these, go to a cmd prompt, and type:
set devmgr_show_nonpresent_devices=1

then, still from the cmd prompt - you need to invoke device manager from there, so type:
start devmgmt.msc

then when it opens, choose "view" then "show hidden devices" again.
See more entries? Notice the "Non Plug and Play" device entry now? Also, any unknown devices with a question-mark will show up.

Windows hides these for a reason, and now that they are all there, you can do whatever you want to clean up, but it's not necessary.

The set command isn't permanent, so you'd need to enter it everytime, or maybe there's a reghack for it - though i haven't looked.

Overall - pretty neat stuff. pbxman
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Wow. There is lots of junk there now! I still can't remove any of the "devices" in the Non Plug and Play folder but it's interesting to know what's there.

I was glad to see "Printers" listed there too when I did this. During an interview a couple months ago, I was asked what steps I'd take to solve a printer problem from a user. Stupid me (nervous I guess) said, "I'd first look in Device Manager to see if there are any conflicts." LOL

It wasn't until 2 days later when I was driving around did it dawn on me that Printers don't show in Device Manager!! Might explain why I wasn't offered the job.... The good news is I didn't really want it anyway (but it's always nice to say, "I'm glad you want me, but I don't want your job!")
 
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