I’m using Windows 7 and Avast! Pro. I accidentally deleted the Avast! gadget from the Windows Gadget list. How can I get it back without re-installing Avast! completelly? I already tried via Control Panel → Install or Change a Program. There I clicked Avast! in the list of programs and tried ‘Repair’, ‘change’, Update…but it doesn’t get the gadget back.
Repair avast unticking gadgets and restart and again repair avast with gadget ticked again and then restart. Hope this may help you… 
Right click on desktop, select “gadgets” (or whatever it is called in english language")
You should be able to activate from there, I guess.
He said he had deleted it from windows gadgets list. Well I didn’t find any option to delete it only Add and uninstall was there. But anyway I think u might have uninstalled so try what I said unless any expert view comes
Run this:
c:\Program Files\AVAST Software\Avast\aswSidebar.gadget
Thanks a lot, doktornotor. Worked like a charm! 
Ashish Singh, you were right, I should’ve written ‘uninstalled’ instead of ‘deleted’, because the latter isn’t an option there.
Thank you all for your help.