COM port in use

[pyrokk]

Hey all,

I have a USB to serial adaptor which i'm trying to get to work on COM 3 and COM4. (it has two serial ports)

When I first got it, it worked fine on these ports, but after plugging multiples of these in and such, I can't get them to work on COM3/4 any more.

It's on COM7 and COM8 right now. If I go in device manager>COM7>Port settings>Advanced, I can't change it to 3, 4, 5, or 6, says they're all in use despite the fact that nothing is on those.

I don't see any keys for these either in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E978-E325-11CE-B
C1-08002BE10318}. There is only the keys for the parallel port, COM1, 7, and 8.

Is there any way to find out what is blocking the ports?

Thanks!

 

[wpshooter]

Could this have something to do with wheather you have the on-board motherboard serial ports enable or disabled in the BIOS ?

 

[bwnv]

Just disconnect the usb stuff and go into device manager and delete ports 3 thru 8. Restart windows and when you plug in the usb stuff should come up as 3 and 4. You were probably unplugging the usb stuff before shutting down windows, in which case the os "remembers" that those ports were in use and assigns new port #'s next time something is plugged in.

 

[pyrokk]

It's not a problem with the mobo serial ports. Those are working fine.

The COM ports in question don't show up in the device manager. All I see there is COM1, COM9, and COM10. (COM7 and COM8 are bugged now to)

I think the software that i'm using to serialize the USB to serial adaptor is causing this. Sometimes it will lock up and not to anything (or be able to close) until the device is unplugged. When this happened yesterday, the device jumped up to COM9 and 10 when plugged back in. Is it possible that the USB device could not be fully unloading when unplugged under certain conditions?