Phone not being recognised as a media device topic

Hi,

I'm sure this is a simple one but I can't solve the problem!

I have a laptop at home with windows XP which, although it will see the phone as a hardware device, will not let me transfer data to/from it. When I select PTP it works fine but nothing happens with MTP. It works fine on the work laptop...

I've tried uninstalling the drivers, re-connecting phone so the drivers are automatically loaded again to no avail. Tried switching on USB debugging too (this seem to kick start the PTP option though). It may have happened when I was loading lollipop on my phone using my laptop, but I can't be sure. I put the SDK(?) folder on my desktop which I have now deleted, although this idea my be a red herring.

I'm sure this is easy, any ideas?

Cheers.