BleepingComputer.com: My computer will not let me download any new programs

So my computer will not let me download any new programs (like limewire, itunes NOTHING)
Everytime I try to a window pops up that says "Runtime error This application has requested the runtime to terminate it in an unsual way. please contact that applications support team." And it says that for every single program everytime!
I have an MDG computer that has Windows vista home premium on it
So when I go into a downloading window on the internet I click download and immediately that window comes up. I hope that my situation is not hopeless