When i open the avast! installer, i always see a message that the avast! antivirus update is not responding. Please give me a fix as i can’t install my favourite AV. 
have you uninstalled your previous used AV before installing avast ?
have you run the vendors removal tool to clear any leftover files that may conflict ?
removal tools found here. http://singularlabs.com/uninstallers/security-software/
Hi Pondus,
Thank you for your quick response(as always). I have uninstalled it through the control panel, but i will run the removal tool and will try again.
reboot after tool is run… then try install
Oh, i forgot- i have Malwarebytes pro. But it won’t do anything. 
I ran the uninstall tool and the problem still persists. :‘( :’(
attach OTL diagnostic log. http://forum.avast.com/index.php?topic=53253.0
Monitoring
Hi,
I have attached the OTL.txt and the Extras.txt logs.
Could you confirm that it is not running in sandboxie
Yes, i can. Sandboxie runs the program only if i select the “Run is sandbox” option from the context menu. Do you think it is a virus that is blocking the avast.setup proccess? 
Hi Pondus and Essexboy,
I have installed Avast Free AV just now after trying 6 times wih no success :). I haven’t changed any files, just trying. Can you see something bad on the logs which was preventing avast from install?
Could you run the Avast uninstall utility to ensure that Avast gets a clean start
Download Uninstall Utility to your Desktop.
Download the correct version of Avast
Avast Free
Avast Pro
Avast Internet Security
Avast Premier
Disconnect from the net
Uninstall Avast via control panel
[]Run aswClear
[]It will offer to reboot to safe mode … Accept that
https://dl.dropbox.com/u/73555776/aswclear.JPG
[*]Once it has rebooted to safe mode
[*]In the Select Product to Uninstall dropdown choose the version of Avast that is on your system.
[*]Press Uninstall
[*]Once complete reboot your system to Normal Mode
[*]Reinstall Avast
Hi, i have run the aswclear utility before installing avast free.
Hmm lets see if removing the bitdefender remnants helps
Warning This fix is only relevant for this system and no other, using on another computer may cause problems
Be advised that when the fix commences it will shut down all running processes and you may lose the desktop and icons, they will return on reboot
Run OTL
[*]Under the Custom Scans/Fixes box at the bottom, paste in the following
https://dl.dropbox.com/u/73555776/OTL_Fix.GIF
:Commands
[CREATERESTOREPOINT]
:OTL
DRV - File not found [Kernel | On_Demand | Unknown] -- -- (aqe5wbqq)
:Files
C:\ProgramData\*.bdinstall.bin
:Commands
[resethosts]
[emptytemp]
[Reboot]
[*]Then click the Run Fix button at the top
[*]Let the program run unhindered, reboot the PC when it is done
[*]Open OTL again and click the Quick Scan button. Post the log it produces in your next reply.
I have attached the fix and the scan logs.
Hmmm lets look really deep
Download the GMER Rootkit Scanner. to your Desktop, it will be a randomly named .exe file .
Before scanning, make sure all other running programs are closed and no other actions like a scheduled antivirus scan will occur while the scan is being performed. Do not use your computer for anything else during the scan.
Double-click the file you downloaded. The program will begin to run.
https://dl.dropbox.com/u/73555776/GMER_Open.JPG
Caution
These types of scans can produce false positives. Do NOT take any action on any “<— ROOKIT” entries unless advised!
If possible rootkit activity is found, you will be asked if you would like to perform a full scan.
[*]Click NO
[*]In the right panel, you will see a bunch of boxes that have been checked … leave everything checked and ensure the Show all box is un-checked.
[*]Now click the Scan button.
Once the scan is complete, you may receive another notice about rootkit activity.
[]Click OK.
[]GMER will produce a log. Click on the [Save…] button, and in the File name area, type in “GMER.txt”
[*]Save it where you can easily find it, such as your desktop.
Post the contents of GMER.txt in your next reply.
Hi, this is the log from GMER.
Could you temporarily disable Privacyware and try again please
Log with disabled firewall (clicked “Firewall OFF-Allow traffic” button and set proccess monitor to off, also set firewall log to off and exited Privatefirewall from the tray icon, but i’m not sure that it was disabled now as i can’t find a guide) . I disabled Avast all shields, and Malwarebytes all protections, also Zemana Antilogger was off. I think all was set to off. Please tell me if something was switched on.