how do i Change network computer password thro command line ??

Clarifications

Use the CUsrMgr.Exe from Windows Resource Kit. Here's the usage info:

D:\Program Files\RKit>cusrmgr /?
CUsrMgr Ver 1.0 Jan98 by G.Zanzen (c) MCS Central Europe
Sets a random password to a user
usage: -u UserName [-m \\MachineName] \\ default LocalMachine
Resetting Password Function
-p Set to a random password
-P xxx Sets password to xxx
User Functions
-r xxx Renames user to xxx
-d xxx deletes user xxx
Group Functions
-rlg xxx yyy Renames local group xxx to yyy
-rgg xxx yyy Renames global group xxx to yyy
-alg xxx Add user (-u UserName) to local group xxx
-agg xxx Add user (-u UserName) to global group xxx
-dlg xxx deletes user (-u UserName) from local group xxx
-dgg xxx deletes user (-u UserName) from global group xxx
SetProperties Functions
-c xxx sets Comment to xxx
-f xxx sets Full Name to xxx
-U xxx sets UserProfile to xxx
-n xxx sets LogonScript to xxx
-h xxx sets HomeDir to xxx

-H x sets HomeDirDrive to x

+s xxxx sets property xxxx
-s xxxx resets property xxxx
where xxxx can be any of the following properties:
MustChangePassword
CanNotChangePassword
PasswordNeverExpires
AccountDisabled
AccountLockout
RASUser
returns 0 on success

Example:
D:\Program Files\RKit>cusrmgr -u Administrator -m \\127.0.0.1 -p NewPassword

Hope this helps.