Red Hat Bugzilla – Bug 578103
[RFE] Tool to Compare Windows Registry Entries
Last modified: 2010-03-30 16:43:32 EDT
Description of problem:
Now that it is possible to merge Windows registry entries  one might also want to compare the registry before and after a merge on Windows guests. Therefore something like virt-win-reg --compare would be very helpful.
Some of the thinking behind this, as Marko & I discussed on IRC:
* Because of string encoding issues, only a computer program can
really compare two registry entries to determine if they are the
* Manual comparison is made even harder because of the large,
scattered nature of the registry, and the fact that entries are stored
The idea would be to have a tool to check whether registry changes
have been made previously. Thus:
virt-win-reg --compare Windows updates.reg
would either produce no output (meaning that all the updates listed
had been made previously), or some output displaying the list of
additional changes that still need to be made.
The implementation is reasonably straightforward: load the original
registries up twice, and make the changes in 'updates.reg' to the
second copy. Then recurse over the two sets of registries to find
any differences, and print those out. Afterwards, discard both copies
since this operation should be non-destructive.
In addition to comparing a regfile against a guest's registry it might be useful to be also able to compare hivefile/hivefile and regfile/hivefile. For example, one could download the system hive from a guest, do "something" on the guest, download the updated system hive and then comparing the hivefiles.
(In reply to comment #2)
> example, one could download the system hive from a guest, do "something" on the
> guest, download the updated system hive and then comparing the hivefiles.
I agree, this is a compelling feature.