The only thing I can think of that causes applications to act funny is installing with an antivirus program running during the installation. If you are running an antivirus program, turn it off, backup your Runtime folder and do a re-install. If you have a constant on internet connection, disconnect from your computer until the install is finished. If Poser will start, start you virus program and re-boot. See if Poser runs or crashes. If it runs OK, reconnect to the internet. Special note if you are trying to run on any type of network you will have problems.

I must remember to remember what it was I had to remember.