Hello Dovvie,
I had the same problem with that viral program Babylon and I was eventually guided through a procedure which enabled me to reclaim my msn browser. You might like to try the following:
Opened IE [or your default browser]
Click on Internet Options
Click on Default browser
Click on Apply
Click on Advanced
Click on Reset IE
Click on Ok
Restart PC.
This procedure worked for me. The Babylon infection may still be lurking in the guts of my PC, but at least I have control of my browser again.
Kind regards
David.