Patent ID: 8612398

Claim:
A system for replacing a potentially corrupted copy of a file on a computer, the system comprising at least one processor programmed to: identify one or more properties of the computer relating to at least one feature of the computer other than the file; identify an existing version of the operating system on the computer; use the one or more properties of the computer and the existing version of the operating system to determine an expected version of the file by issuing a query to an information database that stores information relating to relationships between various operating systems and properties, the query formulated according to the one or more properties of the computer and the existing version of the operating system, and, in response to the query, the information database draws an inference regarding the expected version of the file; obtain a clean copy of the expected version of the file; and replace the potentially corrupted copy with the clean copy, wherein the expected version of the file is identified using a first hash value and wherein replace the potentially corrupted copy with the clean copy comprises: determine whether the clean copy is trustworthy by comparing the first hash value with a second hash value generated based on at least a portion of the clean copy; and replace the potentially corrupted copy with the clean copy only when it is determined that the clean copy is trustworthy.