window sharepoin service web application not starting

my window sharepoint servier web application is not starting. i have run the command
ToStop:
stsadm -o provisionservice -action stop-servicetype SPWebService

ToStart:
stsadm -o provisionservice -action start-servicetype SPWebService

but is replying with this message. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 213, position 1

please can somebody tell me wht to do 'cos our portal is shutdown and we need to get it back running