I also faced the same issue two days back. I struggled for one whole day.. many times a restarted my PC, disabled firewall, started Oracle services manually but no luck...

After one day.. i again restarted the system, turned of my pc's firewall protection, closed some processes from task manager like blackice, blackiced, msnmsgr etc, started the OracleServiceXE and OracleXETNSListener services manually since they were not getting started automaticallly and then my problem was solved.....