Computer stat up problems

Those problems are the worst. Make sure your motherboard is set to report all errors.Try disconnecting everything from the motherboard adding them back one at a time. Try just the video card, hard drive and once piece of memory and see if it starts up normally. If you can't find anything there, try running a memory test program. Memtest86 and Windows memory diagnostic (by Microsoft but doesn't need Windows to run it). If it finds errors replace the memory.