Ok guys, I have seen so many slutions but still why doesn't anybody point out the fact that there is something called "OpenFileDialog" in the toolbar.. you just add that and then

if(openFileDialog1.ShowDialog() == DialogResult.OK)
{
data_string = openFileDialog1.FileName;
}

Or if you want more files just check the multi select option for the openFileDialog and go :

int i;
openFileDialog1.ShowDialog();
for(i=0;i<openFileDialog1.FileNames.Length;i++)
if(doesNotExist(openFileDialog1.FileNames[i])==1)
fileList.Items.Add(openFileDialog1.FileNames[i]);

..if u use a list view control... or just adapt this to whatever suits your needs...

Please take note that I'm somewhat of a begginer at programming and I might be quite off here.. sorry if I missunderstood the topic...