Extra Note on using the shell command is after executing the shell command VB continues to execute statements so doesn't wait to see if the shell process finished or not.
If you need to wait for the process to finish then two options are to have a do loop which just keeps looping until a condition is met, creation of a file for example.
The other method is to use API calls, these are noted in the API forum somewhere can't remember of the top of my head what the calls are. Be aware though that different platforms dont all have the same API calls.