Hello dak1866 and welcome to the forum.

1. What is your OS, 32 or 64-bit? How much RAM do you have?
2. What product of Avast did you install? Free, Pro, AIS?
3. Please check the following to check the settings:
Open Avast GUI > Settings > Updates >
A. Engine and Virus Definitions: If you want your settings at "Manual" or "Ask When Update is Available," this may conflict with "scheduled tasks."
B. Update Parameters: all boxes unchecked (default)
- If you use DSL, you may want to set #2 above to "My computer is permanently connected to the Internet."
- If you use dial-up, you will want to use #2 above to "I only connect to the Internet using dial-up modem."
C. Proxy Settings: Auto Detect using IE Settings (default)
- Some people have found that using "Direct connection / No Proxy" have worked for them.
- Use "Specify Proxy Server" if you use a proxy and complete the information below it for the proxy server > click "OK."
4. Next, what is your firewall (FW) currently and in the past? If you had a different FW in the past, did you use the vendor's uninstaller tool to remove it or another way? Remnants can cause conflicts with security software. Also check to see if your FW is blocking anything for Avast...usually this is the culprit for not being able to connect. Thank you.
5. If all the above fails, try a Repair of Avast: (esp. if you are getting the "Unsecured" alert)
- Go to Control Panel > Add/Remove programs > Avast Antivirus.
- Scroll down and choose Repair function in the pop-up window.
- Reboot.