[Skunkworks] PC access logger [something like that]

Hey, Ideally, am looking for a software [client based or server based] that can monitor PC/SERVER access (folder, files etc). Not to sniff but for LAN security.

In other words, if you logged in to my PC i want to know - alerts too or just logs If you accessed a server A and Y at time C and D i want to know - alerts or just logs may help. Able to store history. Open source or commercial/otherwise.

Something like that.