As the installation runs half way, the dfm version show it already upgraded. My server running on Window 2008 R2 64-bit. May i know which PURGE tool i shall download? I dont see a version which matches my current version i have.
IIRC there is no (supported) way to upgrade from 4.0 to 5.2 directly. Too many DFM and especially Sybase versions inbetween.
As 4.0 is 32bit only and 5.2 is 64bit only, there are also data conversion issues when trying to restore the 4.0 DB backup into a 5.2 instance, which may be the problems you see.
The one way that used to be supported was to upgrdae 4.0 to the latest available 32bit version, which was 5.1. Then convert 32bit to 64bit by importing the 32bit DB into the 64bit version of the same release and afterwards upgrade that version to the latest DFM / Operations Manager 5.2.
Unfortunately all versions prior to 5.2 are EOA and EOS for a very long time now, so you are on your own.
Nevertheless I still found a 5.1 releas on the support site: