Hi.
There might be something in msconfig that you can uncheck. Type msconfig in the Run box then click on the Startup tab.
Another possibility is to rename the registration file. Go to Programs and locate the HP folder. Find the product registration file and right click. Select Properties. Open File Location. It should take you directly to that file. Right click and rename it.
On mine the file is named hpqwrg and can be found in C:\Program Files (x86)\hp\Digital Imaging\bin
Don't rename any hpqwrg files with a dat, dll or rsc extension. The one you want is an application or exe file.