It's dangerous having 2 antivirus applications installed at once so you have to choose which one you want, MSE or McAfee. Having 2 can actually cause issues. Either one isn't perfect and it's common knowlegde that one A/V may catch something one minute that another doesn't, but the reverse could just as easily be true.
Look in the last clickable link in my signature and download Stinger and Malwarebytes Free, run them and see if they catch anything.
On second thought you should perhaps also run Hijackthis and post a log on one of those specialist forums as suggested lower down on that same link.