Hi Ranma344,
I noticed that my Avast was not running, and I was unable to get it to start.
well I too have lost Avast Internet Security-7

I tried a Repair(as Stated) via Programs and Features(un-Install OPTIONS), Rebooted Avast, it[Avast] didn't load at start up I Manually clicked to Start but still Unsecured.
I didn't Fresh install AVAST because if it is a Virus as you think this would only make this Hitch a Major problem.
Follow Avast's steps: Inside Avast Internet Security-7 "Top Right Side"
#01, I clicked "Support"
#02: Generate Support Package 3/4 not the Full Dumps
Only 1.52MB

(I just Generated another Support Package with Full Dumps 4/4 Only 1.53MB's to send off)
I than get a popup "Thanks for...trouble shooting..." with a link
'What do I do now' <---
#03 Clicky Important task! ...your given Help where to find your 'Generated Support Package' .zip file
C:\ProgramData\AVAST Software\Avast\Support\20130206_XXXX_XXXXXXXXXX.zip and than how to upload to Avast/incoming via FTP..
I've downloaded and installed Internet Security-7 with License Key again reboot still System is unprotected, "Fix Now Button" didn't Fix.
regards
Jacksback
PS: I set logged in for 1hour by the time I finished post and the hoop jumping Verification, I lost post

It's been troublesome day! *%^#$! <-- That's Deep breathing and it doesn't help!!