Microsoft.Win32.RegistryKey   rk   =   Microsoft.Win32.Registry.LocalMachine.OpenSubKey( "SOFTWARE ");
String   []   names   =   rk.GetSubKeyNames();
foreach   (String   s   in   names)  
{
//输出吧....
}

------解决方案--------------------

可以用Installer API，详细文档见http://msdn.microsoft.com/en-us/library/aa369426(v=VS.85).aspx。

C# code

static void Main()
{
    StringBuilder result = new StringBuilder();
    for (int index = 0; ; index++)
    {
        StringBuilder productCode = new StringBuilder(39);
        if (MsiEnumProducts(index, productCode) != 0)
        {
            break;
        }

        foreach (string property in new string[] { "ProductName", "Publisher", "VersionString", })
        {
            int charCount = 512;
            StringBuilder value = new StringBuilder(charCount);

            if (MsiGetProductInfo(productCode.ToString(), property, value, ref charCount) == 0)
            {
                value.Length = charCount;
                result.AppendLine(value.ToString());
            }
        }
        result.AppendLine();
    }
    Console.WriteLine(result.ToString());
}
       
[DllImport("msi.dll", SetLastError = true)]
static extern int MsiEnumProducts(int iProductIndex, StringBuilder lpProductBuf);

[DllImport("msi.dll", SetLastError = true)]
static extern int MsiGetProductInfo(string szProduct, string szProperty, StringBuilder lpValueBuf, ref int pcchValueBuf);

------解决方案--------------------

c# 获取已安装程序列表