Installed XP and you feel fuzzy about the new Start Menu? I don’t know how to change the background colour, but I can tell you how to modify the text that appears in that button, and also the bitmap image which, on the side of the menu, reports the current OS version.
This is an example of what you can achieve:


New addition: you can now change the image in the Start button as you prefer, see Neo while he takes the red pill from Morpheus’s hand. You can also change the "Click here to begin" Tooltip, which appears after leaving the mouse on the button, to whatever you want, like "Hack the Matrix!"
It isn’t so immediate though, you don’t need to change simply a registry key, but you have to modify the file explorer.exe (don’t worry, no tough HEX editing, you just need a simple tool).
Disclaimer: if you are a first time user, I do *not* suggest you to use this guide, since, even if it is completely safe and error proof (backups rule), you never know where the border between safety and danger lies. Follow your heart. If you feel even the slightest doubt, do *not* go further. In any case, you can’t hold me responsible for any damage YOU do to your system because of YOUR ineXPerienxe
You need to download ResHack from Download/Tools first. It is a plain compressed version, it has no installer, so you need to create first a folder to put it in, then decompress it in there.
Before running ResHack.exe, make a backup copy of explorer.exe (the simplest way is to drag and drop the file from Windows Explorer in the same folder, pressing the Ctrl key, so a file named "Copy of explorer.exe" will be created).
Now, let’s explain something. Modifying explorer.exe under Windows 95/98 could be just an issue of the file being already open, and anyway the possibility to shift to DOS makes it all easier, since explorer.exe is not runnig and you can change it as you please. Windows XP has instead a file protection system which will, on a regular basis, avoid you from arbitrary modifying any system file (just like explorer.exe), so you will need to start in Safe Mode. I suppose at this point that you made a backup copy of explorer.exe and that you uncompressed ResHack in a folder.
To start in Safe Mode, press the F8 key right after the screen becomes blank (after the POST), and wait for the text menu to come up. Choose to start in "Safe Mode", log in as administrator, press yes to the dialogue. You need Task Manager open now: to start it, use the Ctrl-Alt-Del combination (if you previously enabled the classic logon screen, you may need to press the "Task Manager" button after that, as well). From there, in the "Processes" panel, select explorer.exe and terminate the process. Now, in the File menu of Task Manager, choose "New Task (Run…)", and Browse to ResHack.exe (you remember where you uncompressed it, do you).
Inside ResHack, do [File > Open] and choose C:\Windows\explorer.exe. You will see a tree structure like in Windows Explorer.


The first (and easier) step is over. If you want to go on, and modify also the bitmap on the side of the Start Menu, these are the steps to follow:




Go in [Action > Replace Bitmap …] and in "Open file with new bitmap" browse to the datacenter.bmp you saved before, then in the right side, browse to the bitmap of your current version (in my case it was #167, XP Professional; it is #166 for Home Edition), and hit Replace.
You can obviously change the bitmap to whatever you want to, but don’t ask me if the bitmap width must be the same, I don’t know (since I never tried); in the best case your Start Menu will be "indented" depending on the bitmap dimensions.
And now let’s see how you can change the Start button image and Tooltip. Note that if you use a plain single-line taskbar (the dafault) you shouldn’t put in here something higher than 30 pixels, the image I used is 50 pixels high, because I setted my taskbar on two lines.
Use exactly the same procedure seen before to replace the image located in the Bitmap Resource 143, the very first one, with one of your choice. Obviously the bigger the image, the bigger the Start button.
Now browse to the string table 34, line 533:
Done! Now simply compile the changes, do [File > Save] and reboot normally.
You know the tools and the method, so there are a lot of things you can modify, icons too, even if I’d avoid to play too much with it, because it is time consuming
Enough for now, enjoy.