Help- I cannot scan v5.0.418

I just upgraded from V 4.8- I right click icon>open Avast UserInterface>Scan computer : the page tells me “you can now use the controls below to run a predefined scan”…etc…

however: I cannot click anything, because while there are 4 windows-(below where it says Scan Now)- along with icons which appear to be magnifying glass w computer, disc, etc… the icons cannot be clicked- I’m assuming there should be a description alongside these icons, however the windows are blank…

Running XPSP3, had no problems w the prior version, and no instillation problems…

Can you please help me???

Thanks in advance

I suggest an installation from the scratch and booting after it.
Any other security program that could interfere on avast installation?