Sorry for this long post but the website I got this from is long longer available so I'll just copypaste everything here. These may be the things you already tried with RH but these have always worked for me, so.... here goes, hope it helps:
Remove Microsoft Branding from Boot
Posted on May 7, 2013 by bmosley
When you build an arcade, the most important thing is to try to keep things as authentic feeling as possible. Once you’re in HyperSpin or anything other frontend, things look great and distract you from feeling like you’re sitting at a computer. Maybe the Windows starting cursor/welcome screen/etc don’t bother some people but we didn’t want an arcade with any of that. Most of the info has been taken from different sources so I won’t take credit for all of it. Some people used only certain parts or had custom logins/etc. We wanted a way to compile all the pieces into a simple two part tutorial.
Here’s a video of our start up from cold power-on to running a default HyperSpin set up.
This was all done on Windows 7 64bit Professional and if you’re using something else, your milage may vary.
Some people use Instant Sheller for some of these steps but I find it to not work very well especially in Windows 7 and ended up not liking the results since it didn’t change all the stuff I wanted. Before you try it make sure you have a back up.
Have auto-login turned on for the user. This will bypass the login page. There are tons of tutorials on this so I’m not going to write out the details here but its fairly easy for anyone to do. The actual shelling will be at the very end but we need to get rid of all the junk before it loads first.
MAME Cabinet Speed Tweaks - optional but recommended
Part 1 – Killing Boot Text and Backgrounds
First, grab Windows 7 Boot Updater. This application will save some time from doing things manually but far from all we need to complete the shell.
1. Install and launch Windows 7 Boot Updater.
2. Create a black static image in paint or whatever app you want to use (png or jpg) or just use the one I made here. From the Animation drop down change to “Static Image” and select the black image.
3. In Message 1 tab remove the text in the field and do the same for Message 2 tab’s text field as well.
*If you’re machine will sleep, you can do the same for Resuming tab as well by removing the text.
Click Apply and close the application. Before you restart the machine, change your background color to a SOLID black! (You’ll see why later if you don’t) Restart your computer for the changes to take. The easy part is done.
Part 2 – Remove Branding
Since we’ll be modifying system files in this part, you’ll want to double check you’ve made a backup of everything. I’m a linux guy so I may use slightly different vocabulary for some of the terms here but it’ll make sense while you’re going through it.
First download and install Resource Hacker as we’ll use it soon. Also download and install TakeOwnership (this will allow us to skip quite a few of my original steps) ALL THE FILES THAT WE WILL BE MODIFYING SHOULD BE BACKED UP SOMEWHERE! So back each one up to some folder in case you make a mistake and need to use the recovery console to fix it.
imagers.dll – In Windows explorer, navigate to C:\Windows\System32\ and find the file imageres.dll. Right-click and choose “Take Ownership” from the contextual menu. Then right-click again and copy it to your desktop. We’ll use the file on the desktop for editing.
Launch Resource Hacker as an Administrator (right-click on the app) and open up imagers.dll on the desktop.
Under IMAGE there are a bunch of resources in folders ie. IMAGE/5030/1033 which are backgrounds for the startup/welcome screen. Right-click on these and just deleted each one. Same for the cursor images under PNG as well as Bitmap. They might not all need to be removed, but go ahead and remove them all.
Save the file and move to C:\Windows\System32\ with Copy and Replace.
Restart your machine. Hopefully you see some of the changes so far but we’re not quite done.
authui.dll – In Windows explorer, navigate to C:\Windows\System32\ and find the file authui.dll. Right-click and choose “Take Ownership” from the contextual menu. Then right-click again and copy it to your desktop. We’ll use the file again on the desktop for editing.
Once again, launch Resource Hacker as an Administrator and choose authui.dll on the desktop.
In the column on the left, navigate to UIFile > 12400 > 1033, from here edit the following lines to match. After EACH line you edit, click the Compile Script button at the top of the window and then navigate to the next line.
* Bold indicates changes/additions to original line.
<DUIAnimationStrip id="atom(WaitAnimation)" layoutpos="none" width="20rp" height="20rp" margin="rect(0rp,0rp,5rp,0rp)"/>
<element id="atom(StatusText)" layoutpos="none"/>
<element id="atom(Branding)" layoutpos="none"/>
<button id="atom(Accessibility)" tooltip="true" layoutpos="none"/>
Click the Start Menu and type “cmd” without quotes and enter. At the prompt type ‘mcbuilder’ without quotes and enter. Close the command prompt and restart the computer.
Part 3 – Hiding Cursors from Boot
Remove the cursor and spinner circle that pops up right before windows loads (where the welcome screen used to be). In this part we get to hack the registry which you probably shouldn’t be doing as you can destroy your installation. Chances are that you will anyways, so here it goes.
Basically, we aren’t removing any cursor at all but rather camouflaging it to match the black background. I used two basic cursors that I made in 30secs. I only need two for basic Windows navigation; a simple crosshair for clicking and moving around and a busy cursor so I know when things are still loading/etc). You can snag them here if you want. Drop them or your preferred cursors into C:\Windows\Cursors\
Screen Shot 2013-05-07 at 11.44.36 AM
Click the Start Menu and in the search box type “regedt32″ without quotes. Confirm the User Access Control pop-up.
In the left column, navigate to Computer\HKEY_USERS\.DEFAULT\Control Panel\Cursors
Double click the Value name and change the strings for each of the items to %SystemRoot%\cursors\cursor1.cur OR %SystemRoot%\cursors\cursor2.cur
You don’t really need to change ALL of the cursors like me but it makes it easier to just replace them all. Use the Value names to know which ones your changing if it helps. Once you’re done, exit RegEdit.
Again, this may be optional but it’s not going to hurt, Click the Start Menu and type “cmd” without quotes and enter. At the prompt type ‘mcbuilder’ without quotes and enter. Close the command prompt and restart the computer. You should notice, well… nothing. At least nothing on the screen until Explorer is up and running.