Unable to run simulink

Hi!

When using matlab I have encountered a problem related to simulink. Matlab works fine. When trying to run a simulink model I get the following error: "MATLAB:dispatcher:loadLibrary Can't reload 'C:\Program Files\MATLAB\R2013a\bin\win64\libmwsimulink.dll'. Caught MathWorks::System::FatalException"

I have checked the win64 directory, and it contains the said dll file(Have not tried to open it though, as I don't know which program to use for that purpose).

I suspect that this error may have root in some computer problems I had some days ago, but I fail to see a connection. Until it occured both matlab and simulink were working fine.

Any inputs from you guys that may help a frustrated rookie?