Problems with Avast free antivirus

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Antivirus will not turn on and will not turn on in action centre either. I have tried to uninstall but still seeing the avast symbol with the red x through it on the taskbar. I think I uninstalled it but not sure if I had two avast programs and one was uninstalled while another remains somewhere as I can't see it on my list of programs.  I also tried repairing it but nothing is working. Need help with this as not sure what else to do. 

[Asyn]

- Which avast!..?? (Free/Pro/IS/Premier)
- Which version..??
- OS..?? (32/64 Bit..? - which SP..?)
- Other security related software installed..??
- Which AV(s) did you use before avast!..??

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It is the free version 64 bit. Using windows 7 professional. The other version was avast pro not too sure as it seems to be uninstalled. i haven't used any other antivirus.

[Asyn]

1. Download avast! Free Antivirus: http://files.avast.com/iavs9x/avast_free_antivirus_setup.exe
2. Follow instructions: http://www.avast.com/uninstall-utility (Run this tool for all prior installed avast! versions..!!)
3. Reinstall avast! with the downloaded installer from point 1.
4. Reboot.