how do i change default browser using c# or batch file

Question

title speaks it all.

Answer 1

for the windows 7 pc you need to change registry key for the

HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\ Associations\UrlAssociations\http

you can change that using c#

RegistryKey regkey = Registry.CurrentUser.OpenSubKey("SOFTWARE\\Microsoft\\Windows\\shell\\Associations\\UrlAssociations\\http\\UserChoice", true);
string browser = regkey.GetValue("Progid").ToString();

if (browser != "IE.HTTP")
 {
      regkey.SetValue("Progid", "IE.HTTP");
 }

for prior to vista os - (checked in windows XP)

RegistryKey regkey = Registry.ClassesRoot.OpenSubKey("http\\shell\\open\\command", true);           
string browser = regkey.GetValue(null).ToString().ToLower().Replace("\"", "");
string defBrowser = "";
if (!browser.EndsWith("exe"))
{
        //get rid of everything after the ".exe"
        browser = browser.Substring(0, browser.LastIndexOf(".exe") + 4);
       defBrowser = browser.Substring(browser.LastIndexOf("\\") + 1);
}

if (defBrowser != "iexplore")
{
        Process.Start("IExplore.exe");
    ScreenScraperEngine.Instance.Wait(2000);
    string iepath = "";
    foreach (Process p in Process.GetProcesses())
    {
        if (p.ProcessName == "IEXPLORE")
        {
    iepath = p.MainModule.FileName;                         
        }
    }
    if (iepath != "")
        {
            string iepathval = "\"" + iepath + "\" -nohome";
            regkey.SetValue(null, iepathval);
        }
     }