Showing posts from June, 2015

Access 64-bit HKLM\Software registry by 32-bit C#.NET application

Access 64-bit HKLM\Software registry by 32-bit C#.NET application

While running 32-bit windows application on a 64-bit windows OS their is a registry redirection. Here if 32-bit application try to read a key under HKLM\Software, then due to Registry redirection effective path becomes HKLM\Software\Wow6432Node. For example, we are running 64-bit and 32-bit application to read registry keys as HKLM\Software\xyz and HKLM\Software\Wow6432Node\xyz

So by default with an input of HKLM\Software, 64-bit application will read HKLM\Software\xyz while because of registry redirection 32-bit application will read HKLM\Software\Wow6432Node\xyz.

In C#, to read 64-bit HKLM\Software registry keys we can use RegistryKey.OpenBaseKey method. This method takes two arguments- RegistryHive and RegistryView. Here sperate registry views are present for 32-bit and 64-bit.

Here is the sample C# code to read AppPaths for 32-bit and 64-bit applications installed on the system -


Extract icons of Installed Windows Application using C#. NET

Icon of Installed Windows Applications

First we need to figure out the location of icon for the installed windows application. This information is stored in registry at following locations -
1. Key name - HEKY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
   Value    - DisplayIcon

2. Key name - HKEY_CLASSES_ROOT\Installer\Products\{productID}
   Value - ProductIcon

first try to get location of icon from HEKY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall. Here if the value of DisplayIcon is null then try to fetch location of icon from HKEY_CLASSES_ROOT\Installer\Products\{productID}

Here is the sample code to read the icon -

using system.Drawing //read HKEY_LOCAL_MACHINE Icon ProductIcon; privatevoid ReadIcon() { try { string uninstallKey = @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall"; using (RegistryKey rk = Registry.LocalMachine.OpenSubKey(uninstallKey)) {������������������…