Few days back i did my Oracle Upgrade from 10.2.0.1 to 220.127.116.11 in Windows 2003/ multiple Oracle homes environment. I did it successfully with the help of upgrade guide from SMP.
Oracle upgrade 18.104.22.168 requires 10.2.0.4 version. first we upgrade 10.2.0.1 to 10.2.0.4 then 22.214.171.124.
I have also prepare the notes for the same. if any one requires or stuck on any phase, do let me know.