Can't to promote site server and show grey button

I try to config for promote site server of the client on each branch but I can't check or enable task service and package service

on targer client. I've checked the systems requirement, It's OK. I've tried to reset agent and re-install but the problem still occure. 

My system information:

1) Altiris CMS 7.5

2) OS XP SP3 

3) CPU i5 3.20 Ghz

4) Ram 4 GB

5) IIS 6.0 Compatibility

6) .Net 3.5 SP1

Please kindly help me to solve it.

Thanks.