Acrobat Standard 8.1 waiting

I have just installed Acrobat Standard 8.1.0 on a PC that also has Reader 8.1. I have allowed Acrobat to be the standard program to open PDFs; however, opening even small PDFs results in the the PC going to almost 100% utilization on the microprocessor and taking minutes until it is ready to work. When the same PDF is opened in Reader, it opens and is ready to go in mere seconds. The PC is a 1 year old dual core AMD rated at 4200 mhz, with 1.5G of ram, runing Windows XP Media, so the machine should be able to handle Acrobat. I am assuming that Acrobat is automatically doing some processing of the PDF, such as OCR or something. I would like for Acrobat to open the PDF without the processing (what ever it is doing) and the subsequent wait time. What do I need to do to have Acrobat open in a "dumb" mode to avoid the waiting? Thanks.