I have had Avast free version for some time never having a problem then suddenly been told its not active and my pc is at risk, tried updates cant get them, tried re download ok for a few minuets then reverts to not active, uninstall, repair nothing works also now getting redirect when click on link ok second try help anyone please.
John
try mbam
www.malwarebytes.org
download,install,UPDATE,I REPEAT UPDATE,scan 
post the log,and wait for experts!
Hello johnys and welcome to the forum.
First I need to know the following:
Product: Avast Free
- What is your OS, 32 or 64-bit?
- What version of Avast did you install? 5.0.677 is the latest version.
- What other security software do you currently have or did you have in the past on this machine including antivirus (AV), firewall (FW), and other security programs? If they were in the past, how did you remove them (the vendor’s uninstaller’s tool or another way)?
If I understand correctly, you have been using Avast Free and working fine until suddenly you cannot update, repair, and now are getting redirected (in all browsers or just one?).
First, turn ON Windows Defender (Windows antivirus), make it Resident (on all the time, and update the definitions so you have some kind of antivirus (AV) protection.
Second, check your computer for malware with Malwarebytes’ Anti-Malware (MBAM).
· Download free http://www.malwarebytes.org/ for an on-demand scanner.
· Double Click mbam-setup.exe to install the application.
· After install, click update so you have latest database before scanning.
· Under Settings:
o General: Automatically Save File After Scan Completes is checked off
o Scanner Settings: Check all boxes
o Updater: Download and install update if available is checked off
· Once the program has loaded, select “Perform FULL Scan”, then click Scan.
· The scan may take some time to finish, so please be patient.
· When the disinfection scan is complete, a log will appear in Notepad and you may be prompted to Restart. (See Extra Note).
· Click the “remove selected” button to quarantine anything found. You will find the infection details under the Quarantine tab.
· The log is automatically saved by MBAM and can be viewed by clicking the Logs tab in MBAM.
· Copy & Paste the entire report in your next reply as soon as possible.
If MBAM encounters a file that is difficult to remove, you will be presented with 1 of 2 prompts – Click OK to either and let MBAM proceed with the disinfection process; If asked to restart the computer, please do so immediately.
Third, check the information on the first post of this thread under Virus/Worms for you to check your machine for malware: http://forum.avast.com/index.php?topic=53253.0.
Forth, follow the directions of obtaining the OTL logs. In your post after the MBAM log, post the two (2) OTL logs as an attachment (Additional Options > Attach > Browse (the logs will be on your desktop > Post). We will analyze your information and refer you to one of our malware experts. Thank you.
Please let me know if you have any questions. Thank you.