I thought it might be one of those Intel integrated chips, The preview window is usually set to OpenGL mode by default, change it to SReed & the problem "should" go away. If not then updating the video drivers will be the best option, Windows has some "safe" drivers at startup so you can actually use it, but they're nowhere near being up to date.

Have you got an external hard drive to go with it? that 320Gb is going to fill up fast. ;)

Windows 7 64Bit
Poser Pro 2010 SR1