Does anyone know how to sort this error out-Error code 0x80040509. I've recently bought and installed a copy of Windows XP Home Edition from Play.com and installed it on my laptop. No problem. I've also checked that its authorisation codes are valid on the Microdsoft website-all ok too. Then I install the updates which includes SP3 and when it prompts me to re-start the PC for the final time, I do so with the following error code appearing after the PC starts up: 'This product key is not valid for this media type. Please use the correct installation CD to re-install Windows. Error code 08x80040509'. I cannot do anything on the PC then! I'm not a PC boff and do not undertand why this is happening. I have a legal version of Windows XP, which works fine until I install the updates! I've also seen others on the Net have had the same fault; however, various forums provide various solutions. I need to know which one is correct, because as you know, it takes time to install/repair the Windows installation everytime this occurs and I'm getting ready to trash everthing and get an Apple. Please help???
