Windows 7: Win7 can't boot, can't repair and can't install after BSOD

Hi!

So my problem is that my sis dropped her (luckily empty) mug on my laptop. I was running a game at the moment, which started lagging. It's always lagging a little bit, so I was not surprised. But after 2 or 3 seconds, it froze, the cursor showed up, and I got a BSOD, for about 5 seconds. Then the laptop restarted, and it can't boot. It gets to the Starting Windows message and the windows logo, but then it stops, and after a minute or so, it restarts. I tried using the Windows Startup Repair Tool from the DVD, but when I click "Repair Windows" it changes to an empty screen, and stops. I can move the mouse, but nothing happens for 20 minutes. Same thing when clicking the Install now button. I took it apart, but nothing seems to be broken, everything fits in its place. I believe it is the HDD, but I'm not certain. Unfortunately, not being able to log in, I don't have a dump file, and I can't quite remember what the BSOD screen said. Could you help me?

Have you tried booting from safe mode (F8)?

Have you tried booting from the win 7 dvd?

Safe mode doesn't work either. It starts loading the drivers, it stops for like 15 seconds, then BSOD for a moment and restarts. From the Windows 7 DVD, I can get to the menu, but can't do anything from there. Neither repairing, nor installing doesn't work.

I just got another idea. Could it be the RAM? Only because I can get to the starting windows message, which means the HDD is ok. But I can't boot, can't repair, and can't start installing. And the only common thing in these operations, is the RAM.

All right, problem found. Memtest86 says RAM is ok, so it leaves the HDD.