Few days back i did my Oracle Upgrade from 10.2.0.1 to 126.96.36.199 in Windows 2003/ multiple Oracle homes environment. I did it successfully with the help of upgrade guide from SMP.
Oracle upgrade 188.8.131.52 requires 10.2.0.4 version. first we upgrade 10.2.0.1 to 10.2.0.4 then 184.108.40.206.
I have also prepare the notes for the same. if any one requires or stuck on any phase, do let me know.