OK, I was playing a game on my computer when a blue screen came up saying beggining dump of physical memory or something so I restarted , my computer. When it started again, it checked a disk and deleted a few things. Then it did the windows xp loading thing and an error message came up saying:

'The application has failed to start because shell32.dll was not found. Re-installing the application may fix this problem'. This was one of the things that the computer deleted.

So I click OK and it comes up with the same screen again. I click OK again and it says:

'the Logon User Interface DLL msigna.dll failed to load. Contact your system administrator to replace the dll, or restore the original dll'

What is happening and how can I get my computer working again?

Thanks Addrad320

P.S. Can you tell me why I get this blue screen aswell?