Avast w Microsoft Security Essentials

Does Avast work with MS Security Essentials,

No it does not, since MSE is an actual Antivirus program, if both are installed, there will be heavy conflicts, weird windows errors, etc.

Thank you

To remove it, go to the following website:
http://singularlabs.com/uninstallers/security-software/
It’s listed under [23b]

MSE, in fact, will tell you have an installed a/v program and will ask you to remove it before continuing with the MSE install.