For some unknown reason my computer screen has turned a slightly green colour, dont know why, but i could use some helping turning it normal again

Second problem is a virus in the boot sector called Boot.Malmo and norton keeps saying iv got it but cant get rid of it

Does your monitor have adjustment buttons? Perhaps an Auto set? Did this just happen all of a sudden?

As to the virus I would recommend posting in the Spyware, Adware, Viruses and HijackThis Logs section