It turns out that Mark Russinovich has made tool that compresses the NTUSER.dat slightly. The tool is called Registry Usage and can be found here: https://technet.microsoft.com/en-us/sysinternals/dn194428.aspx . I picked up this trick from watching Ignite videos. I only have small profiles to test on, but this could be worth to test if you are working with big profiles in a remote desktop environment to reduce the size a little. The options are explained here (copied from sysinternals):
usage: ru [-c[t]] [-l <levels> | -n | -v] [-q] <absolute path>
usage: ru [-c[t]] [-l <levels> | -n | -v] [-q] -h <hive file> [relative path]
-c Print output as CSV. Specify -ct for tab delimiting.
-h Load the specified hive file, perform the size calculation, then unload it and compress it.
-l Specify subkey depth of information (default is one level).
-n Do not recurse.
-q Quiet (no banner).
-v Show size of all subkeys.
Here is screenshoots of my profile before and after I ran the tool with the –h option.
(Strange output of size in the tool. Possibly a bug…)
As you can see it does not compress a lot, but 100KB+ is at least something 😉 . And I am guessing that bigger profiles compress a little more. Hope you enjoyed this tip.