RegistryProt is a free registry monitoring program to protect from trojans

RegistryProt is a 100% free, standalone, compact, low-level realtime registry monitor and protector, that adds another dimension to Windows security and intrusion detection. By monitoring important locations and keys in the Windows system registry, RegistryProt will alert whenever a key is added or changed, and then give the option of accepting the key change, reverting back to the original key setting, or deleting the key.