SCCM updates not installing

Hi,

We are using SCCM 2007 in our company. and i am using to to deploy windows updates to the clients. it is downloading and pushing the updates to the clients. but the updates are not intalling on clients. it keeps on there until some one manually cleick intall the udpates.

i want to know from where i can schedule to download the udpates and shcedule to install them on specifec time.

thanks in advance for the help.