+=head1 SUPPORTED SYSTEMS
+
+The program currently supports Windows NT-derived guests starting with
+Windows XP through to at least Windows 7.
+
+The following Registry keys are supported:
+
+=over 4
+
+=item C<HKEY_LOCAL_MACHINE\SAM>
+
+=item C<HKEY_LOCAL_MACHINE\SECURITY>
+
+=item C<HKEY_LOCAL_MACHINE\SOFTWARE>
+
+=item C<HKEY_LOCAL_MACHINE\SYSTEM>
+
+=item C<HKEY_USERS\.DEFAULT>
+
+=item C<HKEY_USERS\I<SID>>
+
+where I<SID> is a Windows User SID (eg. C<S-1-5-18>).
+
+=item C<HKEY_USERS\I<username>>
+
+where I<username> is a local user name (this is a libguestfs extension).
+
+=back
+
+You can use C<HKLM> as a shorthand for C<HKEY_LOCAL_MACHINE>, and
+C<HKU> for C<HKEY_USERS>.
+
+The literal keys C<HKEY_USERS\$SID> and C<HKEY_CURRENT_USER> are not
+supported (there is no "current user").
+
+=head1 ENCODING
+
+C<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 I<--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 L<Win::Hivex::Regedit(3)>.
+
+If you are unsure about the current encoding, use the L<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 I<--merge> it.
+
+=head1 CurrentControlSet etc.
+
+Registry keys like C<CurrentControlSet> don't really exist in the
+Windows Registry at the level of the hive file, and therefore you
+cannot modify these.
+
+C<CurrentControlSet> is usually an alias for C<ControlSet001>. In
+some circumstances it might refer to another control set. The way
+to find out is to look at the C<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
+
+"Current" is the one which Windows will choose when it boots.
+
+Similarly, other C<Current...> keys in the path may need to
+be replaced.
+
+=head1 WINDOWS TIPS
+
+Note that some of these tips modify the guest disk image. The guest
+I<must> be shut off, else you will get disk corruption.
+
+=head2 RUNNING A BATCH SCRIPT WHEN A USER LOGS IN
+
+Prepare a DOS batch script, VBScript or executable. Upload this using
+L<guestfish(1)>. For this example the script is called C<test.bat>
+and it is uploaded into C<C:\>:
+
+ guestfish -i -d WindowsGuest upload test.bat /test.bat
+
+Prepare a regedit file containing the registry change:
+
+ cat > test.reg <<'EOF'
+ [HKLM\Software\Microsoft\Windows\CurrentVersion\RunOnce]
+ "Test"="c:\\test.bat"
+ EOF
+
+In this example we use the key C<RunOnce> which means that the script
+will run precisely once when the first user logs in. If you want it
+to run every time a user logs in, replace C<RunOnce> with C<Run>.
+
+Now update the registry:
+
+ virt-win-reg --merge WindowsGuest test.reg
+
+=head2 INSTALLING A SERVICE
+
+This section assumes you are familiar with Windows services, and you
+either have a program which handles the Windows Service Control
+Protocol directly or you want to run any program using a service
+wrapper like SrvAny or the free RHSrvAny.
+
+First upload the program and optionally the service wrapper. In this
+case the test program is called C<test.exe> and we are using the
+RHSrvAny wrapper:
+
+ guestfish -i -d WindowsGuest <<EOF
+ upload rhsrvany.exe /rhsrvany.exe
+ upload test.exe /test.exe
+ EOF
+
+Prepare a regedit file containing the registry changes. In this
+example, the first registry change is needed for the service itself or
+the service wrapper (if used). The second registry change is only
+needed because I am using the RHSrvAny service wrapper.
+
+ cat > service.reg <<'EOF'
+ [HKLM\SYSTEM\ControlSet001\services\RHSrvAny]
+ "Type"=dword:00000010
+ "Start"=dword:00000002
+ "ErrorControl"=dword:00000001
+ "ImagePath"="c:\\rhsrvany.exe"
+ "DisplayName"="RHSrvAny"
+ "ObjectName"="NetworkService"
+
+ [HKLM\SYSTEM\ControlSet001\services\RHSrvAny\Parameters]
+ "CommandLine"="c:\\test.exe"
+ "PWD"="c:\\Temp"
+ EOF
+
+Notes:
+
+=over 4
+
+=item *
+
+For use of C<ControlSet001> see the section above in this manual page.
+You may need to adjust this according to the control set that is in
+use by the guest.
+
+=item *
+
+C<"ObjectName"> controls the privileges that the service will have.
+An alternative is C<"ObjectName"="LocalSystem"> which would be the
+most privileged account.
+
+=item *
+
+For the meaning of the magic numbers, see this Microsoft KB article:
+L<http://support.microsoft.com/kb/103000>.
+
+=back
+
+Update the registry:
+
+ virt-win-reg --merge WindowsGuest service.reg
+
+=head1 SHELL QUOTING
+
+Be careful when passing parameters containing C<\> (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.
+
+Libvirt guest names can contain arbitrary characters, some of which
+have meaning to the shell such as C<#> and space. You may need to
+quote or escape these characters on the command line. See the shell
+manual page L<sh(1)> for details.
+