>I have a server that has started taking 99% cpu this morning and is absolutely crawling! This happens in safe mode as well, making it very difficult to troubleshoot. Has anyone else run into this problem or have any suggestions? I finally got the services screen to come up, so will try to investigate there.

One other (left field) possibility:
If the server has mirrored partitions and the system is rebuilding a broken mirror then that can slow things down considerablly (but probably not as badly as this).