USB connect starts Windows Explorer on PC
 

USB connect or disconnect starts Windows Explorer on PC. It just started happening. Prior to this it only activated ActiveSync, and Windows Explorer pops up before I select ActiveSync on the phone. The only thing different I've done recently is I had to tether yesterday for a short time. However, I've done that before a few times without this occurring. I tried soft reset, deleting the device in XP Device Manager and having it re-discover it, but it didn't help.

Re: USB connect starts Windows Explorer on PC
 

After Googling some more I found this, and it worked perfectly:
“I found there is a setting about what the PC does when it detects a connection through ActiveSync (and another action for disconnecting). You have to delete those keys.
The Registry Key:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services\AutoStartOnConnect]
and
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services\AutoStartOnDisconnect]
I deleted those keys and it stopped happening. I think something corrupts them. They re-appear later but without the problem.”
Reference: xda-developers - View Single Post - Annoyed ... ActiveSync connection opens Windows Explorer

After performing the above, things were confused for a couple cycles, but then it fixed itself. I haven't seen the keys I deleted re-appear yet, but it works perfectly.

Re: USB connect starts Windows Explorer on PC
 

didn't have to do all of that all u have to do whenever that happens is goto the USB to PC applet under settings and manually select the mode u want then the connection will switch over. I did this all the time on my tp2.

Re: USB connect starts Windows Explorer on PC
 

You don't have to go through all that. The USB to PC applet pops up whenever the USB cord from the phone is plugged in. It takes no action until you to make a choice, and press the Done button, or it times out with the default, which is ActiveSync. As I mentioned, explorer was up before the USB to PC applet, and explorer again popped up when I disconnected the USB. Yesterday, I had changed it from ActiveSync to Internet Sharing, and back to ActiveSync when I was finished. It had not been set to Disc Drive, nor did the keys I deleted, AutoStartOnConnect or AutoStartOnDisconnect, contain explorer.exe. In fact their contents did not make sense. When I Googled the registry keys, I learned what I expected. The key values should contain a path to the app you wish to execute. This is likely why the thread I cited states the key values get corrupted. The launching of explorer might be a default behavior when it doesn't find the path. The poster on the XDA thread states that he found the solution elsewhere by Googling, which indicates this problem was not an isolated incident.