Just give your self READ only to folders you are worried about under the NTFS security permissions.
You can use 2 users one with full control and one that has read only to all your files or even programs(limiting users with permissions is at the heart of NTFS). then ONLY use the full control account when you HAVE to make changes or install programs.
I am sure you will have some programs not liking the restrictions, but it would give the same effect.
Write protection also relies on the reader listening to it AND you can bypass it if needed(my guess is so could a virus programmed to do this).