I had the same problem.
There was a problem installing this hardware: MTP Device
An error occurred during the installation of the device.
The filename, directory name, or volume label syntax is incorrect."
I tried a load of different things to try and resolve, Reverting to WMP10, Copying the MTP driver from a working PC etc etc etc to no avail.
The solution, I finally discovered was to do with the UMDF (User Mode Driver Framework) service. It comes with WMP11, and installs during the setup.
Looking at the UDMF installation logs (c:\windows\Wudf01000Inst.log) - I found that there were errors during installation - I figured that re-installing UMDF might fix the problem. (and it did!) Unfortunatly, as it is not in add/remove programs, I ran into problems trying to remove it. If you un-install WMP11, it does not remove the UMDF dll’s. If the dll’s exist, then the UMDF installer will skip during the re-install of WMP11.
I managed to manually re-install UMDF using the method below.
To find the installer files for UMDF, you need to get them out of the WMP11 Installer.
How to find the installer for UMDF
Run the WMP11 Setup file “wmp11-windowsxp-x86-enu”
(It will extract the installer files into your %TEMP% folder)
Click Start -> Run -> %temp%
Press F3 and search for “umdf.exe”
Copy this file to your Desktop
Cancel the WMP11 Setup.
Now, you need to fool windows into thinking that UMDF is not installed on your computer, by renaming some files. Copy & Paste the following into a Command Prompt.
rename C:\WINDOWS\system32\drivers\wudfrd.sys den_wudfrd.sys
rename C:\WINDOWS\system32\drivers\wudfpf.sys den_wudfpf.sys
rename C:\WINDOWS\system32\wudfhost.exe den_wudfhost.exe
rename C:\WINDOWS\system32\wudfsvc.dll den_wudfsvc.dll
rename C:\WINDOWS\system32\wudfx.dll den_wudfx.dll
rename C:\WINDOWS\system32\wudfplatform.dll den_wudfplatform.dll
rename C:\WINDOWS\system32\wudfcoinstaller.dll den_wudfcoinstaller.dll
Now run the umdf.exe and re-install.
Spent hours trying to fix this, and finally managed to get it working.
Hope it works out for ya, if it does, let me know!