My 7290 no longer connects to the desktop manager, although Windows shows it in USB devices, with no errors. If I run Apploader, and click next, the 7290 reboots everytime.
When I installed BB Desktop on another similar machine, everything works fine, so I suspect the original PC config....anyone seen this behaviour before??
(4.0.1.10 desktop, both PC's have XP+SP2)

On the PC type the following into Command or - create a Batch file;
cd "c:\program files\common files\research in motion\usb drivers"
bbdevmgr.exe /regserver
regsvr32 bbdevmgrps.dll
cd ..
cd rimdevicemanager
regsvr32 rimdevicemanagerps.dll


reboot

Are you able to download a later version of the Desktop Manager, 4.0.0.10 is a little old now?

I saw that trick in another thread, and tried it last week. It didn't help. I've also completely uninstalled (and cleaned up as reg entires, directories, etc) and re-installed, with no resolution.
I double-checked, and it is 4.0.1.10, which is the latest (4.0 SP1) from Rogers. (not 4.0.0.xx)

I also have XP(sp2) and sometimes suffer the USB crashes with the desktop software.
Each time it happens, I disconnect the unit from the cable, close all RIM software on the PC, using task manager if required.
Open the Desktop Manager again (do not open any of its applications) and re-connect the Blackberry.
In a few cases I even had to reboot before the device would connect.

If I connect the device to the cable with Intellisync open I will get a crash 9 times out of ten.

By the way: was regsvr32 rimdevicemanagerps.dll successful?
on some machines rimdevicemanagerps.dll is not in the rimdevicemanager folder and you may need to search for it in order to register it.

I completely uninstalled everything again today, and cleaned any leftovers. I uninstalled all my USB devices, and rebooted. Then I re-installed everything. Still no luck, so I re-ran the batch file Rancor suggested (which I had tried before).
Now everything is working again.
Only difference this time was deleting and re-discovering all USB hubs, etc......maybe that was the trick?

Seems this problem occurs after I boot up Linux, then switch back to running XP again. That's the only common thread I can find in this cycle.
Once again, the handheld is detected (shows USB:<PIN#> in comm connection)
However, the desktop does not recognize that it is connected, and start sync'ing.
Ran the batch file to re-register the DLL's, to no avail.
Will have to try un-installing all of my usb devices again and see if that helps...

If I run the following,
cd "c:\program files\common files\research in motion\usb drivers"
bbdevmgr.exe /regserver
regsvr32 bbdevmgrps.dll
cd ..
cd rimdevicemanager
regsvr32 rimdevicemanagerps.dll

, the BB Desktop sees the handheld (checking in connection setting, USB), but still says "not connected"
When I reboot, it cannot see the bb until I again run the above commands.
I've tried variations, but the problem is back everytime I reboot, so I have not been able to synchronize for the last few days. I also un-installed all USB devices, but haven't re-installed the desktop software.
Last time this happened, I uninstalled everything and re-isntalled it all again, and it didn't work until I stumbled across some combination that fixed it. Haven't been able to figure the exact sequence, as I tried d@mn near everything last time....