I run a HP750 all in one with XP Home & recently had some issues - but not like yours. Mine were to do with a worm stopping my spool.exe which has now been corrected.
A couple of points:
 I assume that you are using the correct disk -there are 2 supplied; one XP/Macintosh, the other highlighted in red 'no XP'
 How did you delete the software? I used the HP own add/remove option and then found that the file was still visible in C>Program Files>Hewlett Packard. I manually deleted these & then used Scrub XP to clear the rubbish out, then re-installed
 I assume that you installed the software then attached the HP 750 to the PC?
If I can help any more, let me know by clicking the envelope beside my name. I have an install disk for this all in one that does not need updates to run - on my system at least.