In order to upgrade it to latest version 188.8.131.52 patch 3, you first need to reimage it using 184.108.40.206 recovery CD and then you can upgrade it to 220.127.116.11.
Path should be like this
Take backup of your current config from ACS 1113 18.104.22.168
Reimage the solution engine with 1113 v22.214.171.124 recovery CD
Restore the database that you took on the 126.96.36.199
Upgrade the ACS SE to 188.8.131.52
Apply the latest patch 3
Reimaging the appliance using 4.2 recovery CD
NOTE: Using the recovery DVD to reimage your appliance erases all data on the appliance hard drive.
Hope this helps.
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The patches are available through the CCO download section.
Regarding the main version software, you will need to open TAC case in order to get hands on the main version, as entitlement needs to be verified.
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