Tatiana,
first of all, don't worry too much - it is
highly, if not completely unlikely that the computer has suffered or will suffer any damage. In the (almost) worst case, a new OS-installation should fix it. This can be time consuming and annoying - and you should make sure that you have a back-up of all (important) data (and screen it for viruses)... but still, it's nothing you couldn't explain to your father (even ignoring the fact that this can happen to anyone nowadays).
Now - I don't know avast!, but assuming that the OS is Windows (XP or Vista), you will probabaly find a logo of/for "avast!" in the system tray (lower right hand corner; perhaps you will have to click on the little arrow pointing to the left to expand it). Double-clicking on it
could produce a window with options - like a Full System Scan; I know it does just that with all antivirus-softwares I have ever worked with.
I couldn't find any info on such a virus by googling it so I cannot give you any particular assistance. Maybe just this: Shouldn't avast! recognize it, try a different scanner (like Avira Antivir:
http://www.free-av.de/). Also, you may want to run Spybot (
http://www.safer-networking.org/nl/index.html) and/or Ad-Aware (
http://www.lavasoft.de/) - both free.
One of these should usually help... if not, please let us know more about your OS and the symptoms.
Best wishes, good luck,
Wolfgang.
****
EDIT: Geoff beat me to it regarding the avast-scan. /
(regarding rinkuhero's post): Do you use an extra keyboard/mouse with the laptop or "just" the integrated keyboard and touchscreen/trackball? Does your keyboard have programmable keys and/or a specific "back" key?