free virus scan issue

I downloaded and ran a free virus scan called "Avast Home Edition 4.5" to attempt to remove a whole lot of trojans that were hiding in my system...during the scan it stopped about 20X to tell me there was a trojan in a certain application and asked if i would i like to delete it...3 of those 20X it said "are you sure you want to delete this, it is a windows application?"...because "repair" was not an option i hit "delete"...now when i go to my desktop i get several error messages...the first one says it cannot find my "LAN" cnnection and another tells me i may not have access to my email and along with the LAN connection problem i cant pull up my internet browser...when i try it tells me that the application "does not exist"...obviously whatever i deleted during this virus scan was something i should not have deleted...if anyone has ANY idea what is happening i would appreciate any advice...i have high speed internet connection thru my local cable carrier and the last time this happened they had to re-assign my IP address...Thanx, Chris