I need to know more information about your machine to answer your question:
1. What is your OS, 32 or 64-bit? How much RAM do you have?
2. What version of Avast did you install? 6.0.1367?
3. What product of Avast did you install? Free, Pro, AIS?
4. What other security software do you currently have or did you have in the past on this machine including:
- Antivirus (AV)
- Firewall (FW)
- Trial versions of AV, FW and other security programs
- Other security software (example: Malwarebytes [MBAM])
- If they were in the past, how did you remove them (the vendor's uninstaller's tool or another way)?
5. Are your MS Updates (if you have Windows) current?
6. Are your software updates current?
7. Are the Avast definitions (updates) current?
8. When was the last time you did any kind of scan in Avast, and if so what kind of scan was it? Did your scan come out clean (no infection)?
9. Did this problem start all of a sudden or come on gradually? If it came on all of a sudden, what were you doing when it started and when did it happen?
I'm sorry for all the questions, but this will help identify issues that are causing problems. Thank you.