I was trying to install Microsoft Exchange Server 2013 Cumulative Update 9 today. During the Rediness check, it reported the issue “There is a pending reboot from a previous installation of a Windows Server role or feature. Please restart the computer and then run Setup again“. I thought it is a normal behavior as I just extended the drive etc. and definitely want to go for a restart. But, even after the restart also, it showed the same issue. Microsoft references says to check for corresponding registry entries and to edit/delete those as explained here: https://technet.microsoft.com/en-us/library/cc164360(v=exchg.80).aspx. But this was not really helpful as I was not able to find the exact registry entries as they mentioned.

Finally, I found the solution in the following way. This is also referred on a registry entry creation:

1. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates

2. Create a DWORD (32-Bit) Value  named as UpdateExeVolatile and set the value as 0

3. Exit Registry Editor and you are done

After performing the above steps, the Rediness Check doesn’t found the issue as it reported previously and was able to install the CU9 sucessfully