The C:\ProgramData\ folder (and its contents) is often hidden by windows, can you even see the C:\ProgramData\ folder ?
If not try changing the windows explorer settings:
Ensure that you have enabled the 'Show Hidden Files and Folders' option and disable hide system files in Windows Explorer, Tools, Folder Options, Hidden files and folders, uncheck Hide extensions for known file types, etc. see image.
I would suggest that you do a clean reinstall of the latest AIS version 8.0.1483:
- Download the latest version of avast, 8.0.1483 http://files.avast.com/iavs5x/avast_internet_security_setup.exe
and save it to your HDD, somewhere you can find it again (if you didn't save your last download). Use that when you reinstall.
- Download the avast! Uninstall Utility, aswClear.exe find it here
and save it to your HDD (it has uninstall tools for all versions).
- 1. Now uninstall avast! - using add remove programs, if you can't do that (as appears to be the case) start from the next step, reboot.
- 2. run the avast! Uninstall Utility, it will request it be run from safe mode (and will handle the boot into safe mode), first for 7.0 and then for 8.0, once complete reboot into normal mode.
- 3. install the latest version, reboot.
NOTE: You will have to have saved your license key as you will need to re-enter that.