Tips and Tricks:
Tip#1: After in-place upgrade on Windows 2008 r2 server, I noticed that there’s a Windows.old folder in my System drive which takes around 10-20GB of space !
now that I have already upgraded in to Server 2012 / R2 and confirmed that all my applications / file are available, I decided to delete Windows.old folder.
Best way to do this, is to use Disk Cleanup Tool.
Start –> Search for “Disk Cleanup” and run this program (If you cannot to locate this program you need to install Desktop Experience Featureshttp://social.technet.microsoft.com/wiki/contents/articles/15221.enabling-disk-cleanup-utility-in-windows-server-2012.aspx)
On driver selection, select your System Drive
Now you will notice that there’s “Previous Windows Installations & Windows Upgrade log files” options available on Disk Cleanup. you can select both of them and click “ok”
you will get a prompt to confirm whether you want to delete. Hit “ok” and proceed.
this will clear windows.old folder and free up disk space on your system drive.
Removing the Windows.old uninstall cache without installing Desktop Experience
Unfortunately you can no longer copy/paste the two cleanmgr.exe files out of WinSxS like you used to be able to do with 2008 (the store is compressed). I found that a few loops of the following will eventually remove the Windows.old upgrade cache from the root of the OS drive.
p.s. run each line manually, the above is not setup as a batch script and will ask for yes / no input. Several runs may be required.