Sudden shut down and weird errorr messages

Hello,

I hope you can help.

Not an expert, but endowed with some logic, so I'll do my best to follow your instructions.

All of a sudden, my Dell Vostro running on Windows 7 Professional 64 shut down, while I was next door, when I came back I saw a black screen. The second attempt of a cold start worked, and the system is back up. But I was prompted for the Windows Key, that I did not have, so I clicked on "Ask later" which led to a message:

"The authenticity of this windows copy is not yet confirmed"

And when the system was up, I got this this error message (translated from German) - that I cannot click away:

RoxioBurnLauncher.exe - Invalid Image

C:\Windows\system32\snmpapi.dll is either not meant to run under Windows or it contains an error. Install the programme again with the original CD, or turn to your sys admin or software supplier for support.

I also had another error message (translated from German) when I tried to open the Word document that I had worked on when the system shut down:

Microsoft Visual Basic for Applications:

Compile error in the hidden module: AutoExec
This error normally occurs when code is not compatible with the version, platform or architecture of this application. If you want further information please click on Help.

By clicking OK though the message disappeared and the document opened. I am not sure if data was lost.
But I checked another document that I was working on with my translation software, and even though I am 100% sure I saved the document, data has been lost.
But any other document I was working on today, is there and saved in the way I saved it.

I am quite worried now though as I don't understand what has happened.
I think just deleting and re-installing said RoxioBurnLauncher might not be enough?!

Maybe I should mention that my laptop has been more noisy the last days than before.

Any suggestions on what I can/should do or check?

Maybe I should mention that my laptop has been more noisy the last days than before.

Well, it doesn't sound good to me.

Before running any tests, I'd copy all important files off of the system immediately to another device to be sure you don't have further data loss.

You weren't specific enough on your model of laptop. So the best I can do is this: http://www.dell.com/support/Diagnostics/us/en/19

If that link happens to match your laptop, I would try the hard drive stress test which takes a couple of hours. If I had to fancy a guess, I would say your hard drive is just about dead, or the system is overheating and has crashed enough to cause some severe file corruption.