Creo Parametric 1.0 License Request Failed

I recently downloaded Creo Parametric on my Windows 64bit laptop. It ran slowly but today when I tried to open the program, a warning showed up stating "license request failed." When I clicked "OK", the program shuts down automatically. I have already tried restarting the computer and have also emailed - but have not received any answers. Any suggestions to fix this ASAP please?