Patent ID: 6986042

Claim:
A computer system comprises at least two computing platforms (S 1 , S 2 ) each having a trusted device (TD), the computing platforms (S 1 , S 2 ) having a communications link ( 10 ) therebetween, wherein the system is operable to move one or more applications from a first of the computing platforms (S 1 ) to a second of the computing platforms (S 2 ); to load software onto said first computing platform (S 1 ); to perform integrity tests on the first platform (S 1 ); and if the integrity tests are passed the system is operable to move the application back to the first computing platform (S 1 ) and load the software onto the second platform (S 2 ); and if the integrity tests are failed the system is operable to return the first computing platform (S 1 ) to the state of the second computing platform (S 1 ).