Does this help?

private void checkedListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (checkedListBox1.GetItemCheckState(0) == CheckState.Checked)
...

did you move or rename one of your forms or maybe even your assembly?

Do you dispose of all your resources after the 1st button click? Do you specify a filename or is it a static filename you are using? sorry for all the questions im trying to determine more or less...

Have you tried:

DateTime.Now.ToShortTimeString();
or
DateTime.Now.ToLongTimeString();

First, have u got any more information on the type of exception you are getting? and what exactly is the error message?

Does this work easier for you? but as they say as long as it works then its all goooood!!!

Hi i have used this method to stop users from opening one of my applications multiple times.

string RunningProcess = Process.GetCurrentProcess().ProcessName;
Process[] processes =...