The whois data indicates HP has owned the domain name for a while, but I wouldn't trust the dates to be correct. Nevertheless, it seems HP does own that domain. And before you check, hpparts.net is a poker site run by a guy in California as a 'buisness'.
whois info:
Organization:
Hewlett-Packard Company
HP Hostmaster
3404 East Harmony Rd MS 68
Fort Collins, CO 80528
US
Phone: 800-524-7638
Fax..: 970-898-2836
Email: hostmaster@HP.com
Registrar Name....: Register.com
Registrar Whois...: whois.register.com
Registrar Homepage: http://www.register.com
Domain Name: HPPARTS.COM
Created on..............: Thu, Oct 03, 1996
Expires on..............: Sat, Oct 02, 2004
Record last updated on..: Fri, Nov 15, 2002
Administrative Contact:
Hewlett-Packard company
HP Hostmaster
3404 East Harmony Rd., MS 68 - Fort Collins
CO, 80528
US
Phone: +1 8005247638
Fax..: +1 9708982836
Email: hostmaster@hp.com
Technical Contact:
Hewlett-Packard Company
HP Hostmaster
3404 East Harmony Rd MS 68.
Fort Collins, CO 80528
US
Phone: 970-898-7023
Fax..: 404-648-1848
Email: Hostmaster@hp.com