I have a Dell Inspiron 530S with Windows XP Professional. Last night I worked until 1230 a.m. doing medical transcription, all systems working fine, and shut down as normal. This morning when I tried to turn on, the fan came on and stayed on and I get a continous four-beep cycle. I have shut down and unplugged everything and replugged several times. My APC backup shows a green light. My router and modem both show all green. This PC is connected by a router cable to my router in another room, and I am typing this note from my other PC in that room. I cannot switch the two PCs due to one being owned by my employer loaded with their proprietary software and not to be used for personal use (as I am doing now to send this desperate plea for help!) I am scheduled to work at 1 p.m. EST and being a computer know-nothing I need help. I have a friend who is very computer savvy but I can't reach him as he is on vacation. Any assistance you can provide will help a very unhappy transcriptionist. I'm sorry I don't know the memory capacity or other technical info. The PC is about 3 years old. It was built by Dell for me when I ordered it.