I have never installed SharePoint. I don't even think you can on Windows XP Pro, but I could be wrong about that.
But I really think that installing FPSE's 2002 probably installs a subset of Sharepoint.
I just learned this:
If I uninstall in IIS the Server Extensions 2002, I can then create web sites using HTTP in VS2005. So it seems that VS2005 doesn't actually use FPSE's to create the web sites. Okay, this is great I thought, but now I can't use FP2003 to create or open web sites. When I try to open a site now in FP2003, I get this message "The Web Server at 'http:/myMachine' does not appear to have Windows SharePoint Services installed".
This is what leads me to believe that FPSE2002 are related to Windows Sharepoint Services.
So, I ran a search at this point for the file you asked about "owssvr.dll". It wasn't on my machine.
I'm going to now reinstall FPSE2002 and see if I can no longer create sites with VS2005. I get back to on that when I am done.