Real joke...
1) Install SJ657EN.exe (or your language???) into XP. Running it just extracts it to a folder. You must also run the SETUP.EXE after the extract to actually install.
2) Install (i.e just double-click) SJ656mu.exe to fix stupid "can't find scanner" problems when actually running the software.
This is what I had to do to get it running in Win2k3 (no supplied drivers in 2k3).
I assume this is the same problem as in XP...
p.s.
DO NOT have scanner hooked up until told to by the SJ657 software...
To get the files just go to
WWW.HP.COM and search on "Scanjet 4300c". EVERYTHING you need is there.
Hope this helps....