auto lock after 30 minutes

[jolinchewjb]

I'm using windows 7 under local company network, I setup never shutdown monitor and harddisk, no screen password protection,

I didn't press CTRL+ALT+DEL to lock the computer, but after I left my desktop for more than 30 minutes, system autoatically CTRL+ALT+DEL and lock my desktop, so how to disable this if I want to leave my desktop for more than 30 minutes?

 

[AddRAM]

Talk to your network administrator.