Check when last check for Windows Updates was performed

Question

How can I check WHEN last check for windows updates was performed - in code (c#/.Net)?

Not WHICH updates are or are not installed, but WHEN last check was performed?

Best of all would be a complete history of when checks for windows updates had been performed, but I can certainly live with only knowing the last check.

Answer 1

Look at this registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\Results

It has 3 sub keys that each provide different information about the different events

• Detect
• Download
• Install

Each key has a LastSuccessTime value you can use.

Answer 2

On Windows 7, 8, 10 you can use following code:

var auc = new AutomaticUpdatesClass();

DateTime? lastInstallationSuccessDateUtc = null;
if (auc.Results.LastInstallationSuccessDate is DateTime)
    lastInstallationSuccessDateUtc = new DateTime(((DateTime)auc.Results.LastInstallationSuccessDate).Ticks, DateTimeKind.Utc);

 DateTime? lastSearchSuccessDateUtc = null;
 if (auc.Results.LastSearchSuccessDate is DateTime)
     lastSearchSuccessDateUtc = new DateTime(((DateTime)auc.Results.LastSearchSuccessDate).Ticks, DateTimeKind.Utc);

• Reference "C:\Windows\System32\wuapi.dll".
• Check whether EmbeddedInteropTypes on reference is set to False.