lock access to C: if on domain

Have XP Pro and Win 7 Pro laptops that I would like to lock the c: drive when they are on the domain at work but be able to write to it when off domain or using laptop offsite. I also assume there is a way to use GPO to do this? Also, what do you do to get the files from the c: drive when the log back on to the domain?

Follow the below method to lock the C: drive on the system:

1. First go to Start and then in search or run type gpedit.msc
2. You have to then go to User Configuration >> Administrative Templates >> Windows Components >> Windows Explorer. Then click on Setting and at the right side you have to double click on an option called "Prevent access to drives from My Computer".
3. You have to then enable it and in its options menu you can block a particualr drive or multiple drives and block every drive that you want.

Thanks, I will try that part on a spare pc I have to see how it works.