Don't think you can do that.....too many pieces...too many places.
Format the HD and include the software when you donate it.
If your paranoid use a product like DBAN.
Then donate the machine and software.
I have an hp compaq nx 9010 and i'm trying to erase all my important files before i donate it. But i dont want to erase my operating system, what software can i use. Free is preferred but it does'nt really matter i just want the job done.thanx.