will not delete

i was having a problem so i tried to delete so i could re install free version. it would not delete everything and when i try again it says a setiface error has occured. tried to re install but same thing. anyone know how i can get it back?

Delete what ?

If you mean uninstall avast, then try a clean reinstall:

Download the latest version of avast http://www.avast.com/eng/download-avast-home.html and save it to your HDD, somewhere you can find it again. Use that when you reinstall. Ensure that you scroll down and select the avast direct download link for the English version and not Cnet as that is for an on-line installation (not what you want to do). - Direct download for avast Home, English version, http://files.avast.com/iavs4pro/setupeng.exe.

Download the avast! Uninstall Utility, find it here and save it to your HDD.

    1. Now uninstall (using add remove programs, if you can’t do that start from the next step), reboot.- 2. run the avast! Uninstall Utility, reboot. If step 1 failed it may be necessary to run this from safe mode, once complete reboot into normal mode.- 3. install the latest version, reboot.