It wasn't completely voluntary. in my case either. My Windows became slower and slower. In the end, booting lasted a quarter of an hour. And Poser renders would sometimes pause in the middle for no apparent reason. (On a dual Xeon quadcore with 36 GB RAM). Then, the bootsector was damaged. Windows did not boot at all and there was no way to repair it. So I got myself a new harddisk and did a fresh install of everything. Replacing my normal SATA II HD with an SSD drive didn't hurt either. Poser is installed on an external drive, but benefited anyway. Windows boots in under a minute and Poser both starts and renders much faster.