using mcpwatermark editor is not good because it will removes windows branding image also .....so below procedure removes only watermarks without any problems
open this location in windows installation drive -->windows folder-->system 32 folder-->en-us folder copy below and replace original file with this
Need basebrd.dll.mui from C:\Windows\Branding\Basebrd\en-US
Need shell32.dll.mui from C:\Windows\System32\en-US
shell32 download
replace original file with this file done. and enjoy.....
note:if it asking for permission then do it as administration
if not possible to change administration previliges then use this tool try again
dual/or multiboot systems can easily with another os...open second os then find path to first os.then you can replace these files with out any permissions enjoy