I am trying to backup through Windows 7 onto an external hard drive however when I get to the point where I click backup and protect an error message pops up that says "The system cannot find the file specified (0X80070002) so I can't go any further with it. Can anyone tell me how I fix this so that I can get my laptop backed up ?

Since you didn't tell us anything about your computer or what you are using to backup I can only guess that you are using windows backup on Windows 7. If that is the case under the start menu browse to Command Prompt (under accesories) and right click on it selecting run as administrator. In the black box type in sfc /scannow. Let us know if it works after that. Also if you need further help we need to know more about your computer. If you are using a program other than windows backup we need to know what.

Sorry if I wasn't clear I am using Windows 7 64 bit and backing up onto an external hard drive using the Winows backup. I have 4 GB ram but that's all I know except that it is a Samsung R540. I am a complete novice at computers so you will have to reply in layman's terms. I have been on the Windows website and found a page that I thought would work, but it didn't it just said the update wasn't compatible with my computer. Can you put your instructions a little simpler so I can try and follow them step by step.

Try this: SFC /SCANNOW to Repair Windows 7 Files | Captain Debugger

Thanks for the suggestion but I tried that and it didn't work, can you think of something else I could try ?