virt-win-reg - Export and merge Windows Registry entries from a Windows guest
virt-win-reg domname 'HKLM\Path\To\Subkey'
virt-win-reg domname 'HKLM\Path\To\Subkey' name
virt-win-reg domname 'HKLM\Path\To\Subkey' @
virt-win-reg --merge domname [input.reg ...]
virt-win-reg [--options] disk.img ... # instead of domname
You must not use virt-win-reg with the --merge option on live
virtual machines. If you do this, you will get irreversible disk
corruption in the VM. virt-win-reg tries to stop you from doing
this, but doesn't catch all cases.
Modifying the Windows Registry is an inherently risky operation. The format
is deliberately obscure and undocumented, and Registry changes
can leave the system unbootable. Therefore when using the --merge
option, make sure you have a reliable backup first.
This program can export and merge Windows Registry entries from a Windows guest.
The first parameter is the libvirt guest name or the raw disk image of a Windows guest.
If --merge is not specified, then the chosen registry
key is displayed/exported (recursively). For example:
$ virt-win-reg Windows7 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft'
You can also display single values from within registry keys, for example:
$ cvkey='HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion' $ virt-win-reg Windows7 $cvkey ProductName Windows 7 Enterprise
With --merge, you can merge a textual regedit file into
the Windows Registry:
$ virt-win-reg --merge Windows7 changes.reg
The program currently supports Windows NT-derived guests starting with Windows XP through to at least Windows 7.
Registry support is done for HKEY_LOCAL_MACHINE\SAM,
HKEY_LOCAL_MACHINE\SECURITY, HKEY_LOCAL_MACHINE\SOFTWARE,
HKEY_LOCAL_MACHINE\SYSTEM and HKEY_USERS\.DEFAULT.
You can use HKLM as a shorthand for HKEY_LOCAL_MACHINE, and
HKU for HKEY_USERS.
HKEY_USERS\$SID and HKEY_CURRENT_USER are not supported at
this time.
This program is only meant for simple access to the registry. If you want to do complicated things with the registry, we suggest you download the Registry hive files from the guest using libguestfs(3) or guestfish(1) and access them locally, eg. using hivex(3), hivexsh(1) or hivexregedit(1).
virt-win-reg expects that regedit files have already been reencoded
in the local encoding. Usually on Linux hosts, this means UTF-8 with
Unix-style line endings. Since Windows regedit files are often in
UTF-16LE with Windows-style line endings, you may need to reencode the
whole file before or after processing.
To reencode a file from Windows format to Linux (before processing it
with the --merge option), you would do something like this:
iconv -f utf-16le -t utf-8 < win.reg | dos2unix > linux.reg
To go in the opposite direction, after exporting and before sending the file to a Windows user, do something like this:
unix2dos linux.reg | iconv -f utf-8 -t utf-16le > win.reg
For more information about encoding, see the Win::Hivex::Regedit(3) manpage.
If you are unsure about the current encoding, use the file(1) command. Recent versions of Windows regedit.exe produce a UTF-16LE file with Windows-style (CRLF) line endings, like this:
$ file software.reg software.reg: Little-endian UTF-16 Unicode text, with very long lines, with CRLF line terminators
This file would need conversion before you could --merge it.
Be careful when passing parameters containing \ (backslash) in the
shell. Usually you will have to use 'single quotes' or double
backslashes (but not both) to protect them from the shell.
Paths and value names are case-insensitive.
Registry keys like CurrentControlSet don't really exist in the
Windows Registry at the level of the hive file, and therefore you
cannot modify these.
CurrentControlSet is usually an alias for ControlSet001. In
some circumstances it might refer to another control set. The way
to find out is to look at the HKLM\SYSTEM\Select key:
# virt-win-reg WindowsGuest 'HKLM\SYSTEM\Select' [HKEY_LOCAL_MACHINE\SYSTEM\Select] "Current"=dword:00000001 "Default"=dword:00000001 "Failed"=dword:00000000 "LastKnownGood"=dword:00000002
"Default" is the one which Windows will choose when it boots.
Similarly, other Current... keys in the path may need to
be replaced.
Display brief help.
Display version number and exit.
Enable debugging messages.
If using libvirt, connect to the given URI. If omitted, then we connect to the default libvirt hypervisor.
If you specify guest block devices directly, then libvirt is not used at all.
In merge mode, this merges a textual regedit file into the Windows Registry of the virtual machine. If this flag is not given then virt-win-reg displays or exports Registry entries instead.
Note that --merge is unsafe to use on live virtual machines, and
will result in disk corruption. However exporting (without this flag)
is always safe.
When merging (only), you may need to specify the encoding for strings to be used in the hive file. This is explained in detail in ENCODING STRINGS in the Win::Hivex::Regedit(3) manpage.
The default is to use UTF-16LE, which should work with recent versions of Windows.
hivex(3), hivexsh(1), hivexregedit(1), guestfs(3), guestfish(1), virt-cat(1), the Sys::Guestfs(3) manpage, the Sys::Guestfs::Lib(3) manpage, the Win::Hivex(3) manpage, the Win::Hivex::Regedit(3) manpage, the Sys::Virt(3) manpage, http://libguestfs.org/.
When reporting bugs, please enable debugging and capture the complete output:
export LIBGUESTFS_DEBUG=1 virt-win-reg --debug [... rest ...] > /tmp/virt-win-reg.log 2>&1
Attach /tmp/virt-win-reg.log to a new bug report at https://bugzilla.redhat.com/
Richard W.M. Jones http://people.redhat.com/~rjones/
Copyright (C) 2010 Red Hat Inc.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.