Product Firefox Release Channel release Version 50.1.0 Build ID 20161208153507 OS Windows 7 OS Version 6.1.7601 Service Pack 1 Signature: chtbrkg.dll@0x1c3e1 chtbrkg.dll = Adware ------------------ You may have ad / mal-ware. Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article. Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.