avast 5.0 security keep detecting and removing files from a program ,that was excluded from scanning , not only but other files like internet explorer or mozilla stop working .internet is good but no connection with browser.
There are exclusion lists for File Shield and for on demand scannings. Check both 
It will be good you submit the offending file to www.virustotal.com to be sure they’re clean.
Also, if it is the case, inform avast of the false positive.