Unable to connect to Internet

After using Zone alarm for many years and on a friends recommendation i have downloaded comodo V2.4.18.184
But on installing the firewall I find i am unable to connect to the Internet !!

I have watched the installation video and have done as suggested ( search for new applications ) ( create a trusted zone for my router) but to no avail.
Some of the error messages are (Avast will not be able to protect incoming POP 3 protocol )

(Check if mail scanner ashmaisr.exe is not blocked by your firewall.)

(I also get IMAP protocol and SMTP protocol warnings .)

Error 10022

I have made sure any previous firewall software has been removed by using the software uninstaller also revo uninstaller.

I would be most grateful for any advice as I really like Comodo and would prefer to use it if i can .

At present i am behind a windows firewall which allows Internet connection
If you could keep any replies as simple as possible as i am a bit of a computer numty

i am using XP