MSS Personalization changes not reflecting to all users

Hello,

Currently we are using SAP user ID XYZ to do the portal personalization changes.  For this user ID in

i) ECC SU01 (LANGUAGE is maintained as English and COUNTRY is not maintained) and

ii) In portal language is maintained as blank.

Now when we use this user (XYZ) for doing personalization, Portal is taking browser defined language which is maintained as English (United States) [en_us] for doing the personalization. After the changes we are able to see the personalization changes for all the users who are maintaining their browser as well as portal language as English (United States) [en_us]. But for other cases (if not en_us) personalization changes are not appearing.

Is there any central way to maintain the language for users so that portal will not refer the language maintained in browser?

(If not it will be difficult (and may be not feasible) to communicate to all our Users to change their browser Language setting to a common language ( i.e.,English(United States) [en_us]).)

Please advice.

Thanks in Advance.