One way you can monitor websites that are viewed is to either upgrade your existing firewall or install a separate proxy server that is able to block, monitor and report on a daily basis websites that are viewed.
Data is recoverable depending on the extent of the problem.
We have an in-house department that specialises in the repair of computers. We then provided you with a DVD or CD with the data you require.
Of cause we would advise all our customers to take regular backups of any important data.