bruce123

beeceebee, it was the pulling out the memory boards and replacing them that got it going again. And I have now turned the computer off to save the CPU from failure. many thanks

That sounds terrible! Yes I did clean off the heat sink paste, I was reading a few posts on that issue. I will try and get some more paste and apply it. Many thanks

beeceebee, thank you - it seems to have worked!! It's amazing! I am now booting it in safe mode and have all my fingers crossed that it will be ok. Thank you so much, I was reading another post about a similar error to mine and it was suggested that the hard drive was broken. Thanks also for correcting me on the memory boards - I'm a novice.

My computer was not booting up and freezing the whole time so I decided to try and clean it. During cleaning, I removed the heat sink and the CPU chip that resides beneath, I then replaced it back as I had found it. I then removed the battery that sits on the board and replaced it, I then removed what I think are the two processor boards, cleaned them and replaced them back. All the cleaning was done with a soft cotton cloth. I then plugged the computer back up and now it won't boot, it is like the start up settings are lost. It just says that a read error occurred, press control-alt-delete to restart. Please help - what can I do to get it going without losing all the data on my hard drive. Thanks