Problems after using Malwarebytes

[Stuart98]

A few months ago, I used Malwarebytes to clean up a computer from Antivir Solutions Pro, so after being infect with a similar "Wolf in Hunter's Clothing", XP AntiVirus 2011, on a different computer I tried the same process and eventually got Malwarebytes set up by using the "Run as 'user'" command to set it up, and then deleted the 36 infected objects found by a quick scan. After restarting, however, most .exes including "rundll32.exe" are coming up with the "Choose the program you want to use to open this file". This is keeping me from using many applications. Assistance would be greatly appreciated. Thanks in advance!

[Firefox]

Hello, and Welcome to Malwarebytes

Since this was caused due to an infection, more than likely part of the infections is still affecting your computer, please follow the instructions below....

If you think you are infected, here are the steps needed to get your computer cleaned....

Please read the following so that you can begin the cleaning process:

You have 3 Options that you can choose from as listed below:

[*]Option 1