Hi Newbie here, basic skills. Turning on what has been a very stabe system for 5 years it runs for a few seconds, fans on, black screen, as soon as the two cd drive lights start to flash, fans go off for a second or two and then the whole thing recycles. I noticed recently that on start up the screen was Ok then would disappear and come back of its own accord a few times before it settled down. Mouse cursor was sticky jerly for a while too. I managed to get it to boot this morning only by continually pressing the restart button on the tower. It eventually booted. No new hardware or software installed recently. I'm now worried about ever turning it off! Running AVG free. Most recently ran AML free reg cleaner reg, where i noticed it had a problem with MS silverlight errors but that's all. Please be gentle with me. If this is a hardware problem the most I've ever done is change a case fan. Thanks to anyone who can give me any guidance.