How to protect the admin password? Or how to lock out unauthorized users? If you want to really protect the contents of your computer - have a look at TrueCrypt. It's free and open source. http://www.truecrypt.org/
actually i require it for folder protection of windows vista folders, simply protecting existing folders with a password
You can do this with TrueCrypt - I've got a 4GB TrueCrypt volume that I use for nearly all my work files - as soon as I mount it (which requires a password), it shows as an additional drive letter, and decrypts/encrypts on the fly. I simply mount it on startup, then read and write from the drive as if it were a physical hard disk. Because the data on the drive is always encrypted, once I dismount it, or turn off my PC, then the data is immediately inaccessible. If you want to protect system folders that need to be in a specific location (e.g on the c drive), then this obviously won't work. You can however use TC to encrypt your entire system drive. But that's probably overkill. Apologies for crapping on about it, but it's some of the best software I've ever used