Well, it's a long story, but to explain the most important things: Around three weeks ago, Windows XP Pro SP2 crashed (the well-known blue screen showed up) and I had to restart my computer. When Windows was starting up, I was told that Windows was damaged and I could fix the problem if I had the original CD and repaired the installed version. I did that, and it worked. I restarted my computer again and a new error message told me that NLDTR was missing. I formatted my hard drive and installed Windows again. The first time Windows crashed during the installation. I tried again and 1 hour later Windows was installed. I thought I had fixed the problem, but ... around 2 hours later I got the blue-screen AGAIN and I had to reinstall Windows. I installed my new hard drive today and installed Windows, and just a few hours later Windows restarted and I found the messages above in the Event Viewer. That's why I'm worried ... I just want to find out what the problem is and what's causing it.