cosimulation of simulink and modelsim

i m asking regarding cosimulation o simulink and dmoddelsim. while using VSIM command it is showing this error " Error using ==> hdlsim>l_GetModelSimLauncherInfo at 957 In GUI mode, white-space characters are not allowed in the absolute path of startupfile: "C:/Program Files/MATLAB/R2011a/compile_and_launch.tcl". Change rundir property value or current MATLAB directory to have a value without white-spaces.

Error in ==> hdlsim at 235 launcherInfo = l_GetModelSimLauncherInfo;

Error in ==> vsim at 101 hdlsim(pvpairs{:});. my matlab version is 2011a and modelsim version is modelsim PE student version,now what should i do now, pls tell me asp as my whole work is on hold