[Galaxy Tab 10.1 Q&A, Help & Troubleshooting] Hogwit:
New Version of KIES is available

Been having exactly the same problems with my (never rooted) new in January GT-P7510 since the last firmware/KIES2 upgrade. Have tried all the fixes in XDA and other forums - wasted hours to no effect. Ended up with 15 device entries for 7510 in my Windows 7 (64) Autoplay list.

Try dowloading the latest KIES_2.2.0.12014_18_8.exe released 8 Mar 2012 from Samsung support. First uninstall both the SAMSUNG USB Driver for Mobile Phones and then Samsung Kies using Control Panel/Programs & Features before you run the new KIES installer.

When KIES finishes installing itself and the USB drivers, fire it up and you'll get KIESPDLR.exe wanting to make changes. If you allow this you'll see the message "There are new components for SAMSUNG KIES.... updates for firmware management ... do you want to upgrade now?" - cancel this as it will not change anything and other posters have said it causes the connection problem.

You're ready to plug in the Tab USB cable now - don't get too excited though there are problems coming. Plug in the 7510 USB cable - preferably in a motherboard USB socket, rather than a hub-based USB socket. The usual storm of device driver installation follows - the first of which always seems to fail - "SAMSUNG USB Mobile Device driver instal failed". Leave KIES to do its thing and you'll get the same error as previously "Cannot start service on this device. Disconnect and reconnect...". Do this and the same thing happens, but this time no new drivers are installed. Stay in KIES and disconnect the 7510 and run the KIES troublshooter under Options - this reinstalls the USB drivers and which manages to get the SAMSUNG Mobile USB Composite Device installed OK this time (and adds yet another 7510 device to your Autoplay list as a bonus...). Reconnect the 7510 and you'll be no further forward - same connection problem followed by error and request to restart the PC. Leave the 7510 connected to your PC and restart the PC.

On restart you should arrive at your usual desktop with no new deice driver installation. Go into Control Panel/Devices & Printers and you'll see a GT-P710 device with an exclamation against it - "Device cannot start - Code 10" error. Click on the "Troubleshooting" option and it will offer to reinstall a driver so let it apply this fix. It will fail on the SAMSUNG Mobile MTP Device installation however. Now unplug the 7510 and plug it back in again. Yet another attempt to install a device driver follows - this time successful so you should see "GT-P7510 installed - ready to use". Followed by the Windows Autoplay box popping up - just close it as soon as you see it. You'll also see the KIESPLDR requests popping up requesting changes to this computer. Cancel these as before.

Now it gets silly - with the 7510 plugged in (KIES hasn't fired itself up) go into Tab Settings, Wireless and connect via Wi-fi - confirm permission on the PC and KIES will start up - and amazingly - connects via USB! From now on you should be able to disconnect and reconnect the 7510 and get a more or less immediate USB connection.

I apologise for the sheer length of this post, but it's a consequence of SAMSUNG's total ineptitude at writing driver installation scripts - who knows what works, or where or why? Any chance of some decent logging/diagnostics options for your cr*ppy KIES connection process Mr Samsung??

Rant over.

And out.

Good luck!