Hello anyone who can help me,
So two days ago, I booted up my computer and it had me run a system repair. I didn't think much of it, but upon finishing the computer restarted and when it booted up, it went to a black screen that said "Replacing invalid security ID with default security ID". Today, it finally finished, 750,000 files later. After it finished, it went directly to a black screen with just the mouse pointer on it. I waited about twenty minutes, but nothing happened. So, I rebooted and started in safe mode, but the same problem occurred. And then the same thing for safe mode with networking and safe mode with command prompt. I don't know what to do next. My computer is a Dell Inspiron 540, with an upgraded processor: AMD Phenom II Black Edition Multi-Core Processor, and an upgraded graphics card: ASUS HD6770, with Windows 7-64 bit. I will give any other information required. Please help me.