So you are talking about checking over the internet. You will need to create a seperate exe to (these are searchable terms (google/yahoo))...
1.)Check Internet Connection
3.)Open statement, Line Input Function, Close Statement, FreeFile Function
So the suggested process would be to...
1.)Check the internet connection to see if it is active
2.)If active then download text file that has the information to the latest exe version
3.)Open, Read, Close text file and check to see if current running exe is the same version or not.
4.)If not, launch secondary.exe to download new exe and end primary.exe
5.)Secondary.exe launches, waits a couple of seconds for primary.exe to end and then uses URLDownloadToFile to copy exe from http source to local drive.
6.)Secondary.exe then uses shell or shellexecute to launch primary.exe
NOTE: This version will only work if you do not add dependancies between versions. If you do then you will need to download a new setup package and use that to install a new version.