I use a crt display and I have tested it and it works as expected. b4 this there has been power unstability in my place and I do not have a ups, hence there are high chance this might have caused the problem. A month ago I added a new hdd (10gb)which was a second hand sale. I use kaspersky 6.0 as an antivirus. I somehow suspect the motherboard because I have tested the other devices (1gb RAM, 80gb hdd) and they all work properly. b4 this booting could fail but after unplugging and plugging back the motherboard devices it would boot normally.