Hi, all.
I, too am having similar problems, with the spoolsv.exe error, Win 2K, Adobe software and Epson 870 printer.
I don't have the background to explain any of all this, and I now have workarounds that are acceptable to me (thanks to copious assistance from my son, without whom I would be still struggling). I am posting my experience with the problem(s) in the hope that others much more expert in the field can glean some vital clue.
1. If I try to print an image file from within Adobe Photoshop (whether in version 5 light edition or version 6 complete) to my Epson 870, I get the error if the spooler is involved. ie whether the spooler is set for immediate printing or to wait until the last page has been spooled, up comes the error message, and away go all of the printer icons in Control Panel.
2. Generally the printer icons return with a simple restart. Once only I found that they were still missing even after a full shutdown; turning off the Epson and restarting brought them back.
3. Setting the printer options to print direct to the printer 'cures' the Adobe-to-Epson problems.
4. Printing from Adobe Photoshop to my other printer (ancient Canon BBJ330 B&W) works like a charm, even with the spooler set to start printing immediately, and with a 'huge' image file (the *.PSD file is nearly 200 MB).
5. Printing from any of the other photo-editing programs available to me (ie MS Imaging, Paint Shop Pro 7, Polyview 3.64, Color Pilot 4.00, EZ Photo 2.6) gives me satisfactory printing even when set for immediate printing via the spooler.
6. I do not 'appear' to have any bitware installed on my system. A search right through all 7 partitions of my hard disks for files bw* turns up nothing. There is, however, an entry in my registry for bwagent.exe. I have not yet tried doing a manual edit of the registry to get rid of any such entries, since my simple logic suggests that if bwagent.exe is not on my hard disk, the registry entry should be fairly harmless.
7. The workarounds which are quite acceptable for my use are either to avoid Adobe entirely, or if there is something in unique about Adobe Phoroshop that I just must use, then cut the spooler out of the loop.
With luck, there is a clue in there somewhere; all we need now is the right technical Sherlock Holmes

.