you had "unintended fingers" on your touchpad? hmm, I think you should look into resolving that issue first.
As far as resolution, right click on the desktop, go to properties>settings>select the resolution you want and click ok. (this is for xp)
for win7 you have to right click on desktop and navigate to resolution settings from there (exact menu choices escape me at the moment)
Alternatively, you want to make sure that your DPI settings are what they used to be, because that can make everything appear bigger/smaller as well.
DPI settings can be changed in advanced settings from the same place you change the resolution