Domain Joining

Dear all

i am trying a winXP machine to add in windows

2003 server , but , i am getting , domain controller could not be contacted.

I had given Gateway , Ip , correctle.
I getting pinging also.
I added suffix for that pc also.
Machine Os: Win Xp with Sp2
config : P4 1.96Ghz / 256Mb RAM / 40 Gb IDE Hdd

Pls help me out.

Regards,

Anand