schtasks.exe - enable schedule task from windows 2008 -

i trying enable , disable schedule task on windows server 2003 r2 windows server 2008 r2 machine.
using username , password. error given access denied.
following command
schtasks /change /disable /tn <taskname> /s <remoteserver 2003r2> /ru <username> /rp <password>

the issue user running schedule task. added user admin group. issue resolved.