Windows 7: prevent reinstallation of windows by other isers!

is there a way so that windows installation through dvd using boot can be prevented? as anybody who knows installation can install windows to remove password. and is there a way so that local users on a pc cannot use usb ports and other external devices?

You should be able to put a password on your bios so the boot order cannot be changed away from HDD first

Edit..
Didnt think about the F8 on startup......thinking...

It's possible to disable the USB ports in the BIOS settings. It's also possible to disable the optical drives. I've seen it done in a secure facility.

Of course, the BIOS password can usually be reset by clearing the CMOS, which may require opening the case.

I doubt that there's any practical way to lock down a PC from users with unlimited physical access to it.

actually i am asking about laptop so not possible to open. well putting password on bios cant solve as by pressing f8 it can be changed.well disabling usb and dvd drives from bios is last option isn't there any software for this?

I just not getting this at all. Is this laptop yours and is it in your control?
What are you trying to stop others from doing if you are in control of this laptop?
If you laptop is stole any thing can be done to it; they now have the time?
If the information on your computer is your concern, encryption might be what you are looking for.
Knowing what you are trying to do and why would help.

well i am asking because in college your room partner can also use it and you cant refuse him. while he may be a local user he can insert a pen drive which may contain virus or he can try to install new windows and you cant kill him for that so prevention better than cure.is there a way so that windows can be prevented from install using dvd boot?

Password Windows 7 to keep out most others.

If you're worried about more serious intrusion, password the BIOS.

I dont' know where you got the idea a BIOS password can be changed via F8 but there is no F8 menu until you can boot into Windows 7 - and you cannot boot anything at all with the BIOS locked via password.

Just don't lose the password. Make it something you never forget like a childhood phone number followed by the full formal name of your childhood imaginary friend.

Greg has some great ideas but mine is simple. DON'T let anybody use the laptop when you can't trust them not to change things.