How to close 32 bit and 64 bit programs in C#

[SilverFire]

this code works to close 64 bit programs after i pick the program.
private void btnSleep_Click(object sender, System.EventArgs e)
{
string processName = ExtractProcessName(ofdBrowse1.FileName);

foreach(Process p in Process.GetProcesses())
{
if(0 == String.Compare(processName, p.ProcessName, true))
{
p.CloseMainWindow();
}
}
}

private string ExtractProcessName(string fileName)
{
string processName = fileName;

int index = processName.LastIndexOf("\\");

if(-1 != index)
{
processName = processName.Substring(index + 1, processName.Length - index - 1);
}

processName = processName.ToUpper();
processName = processName.Replace(".EXE", "");

return processName;
}

How can I get this code to close both 32 bit and 64 bit programs?