CrossOver which enables running many Windows applications without having to install Windows.VM Fusion is software virtualization that enables running Windows concurrently with OS X. VM Fusionand Windows XP, Vista Business, Vista Ultimate, or Windows 7.Parallels is software virtualization that enables running Windows concurrently with OS X. Parallels Desktop for Mac and Windows XP, Vista Business, Vista Ultimate, or Windows 7.Boot Camp enables you to boot the computer into OS X or Windows. Follow instructions in the Boot Camp documentation on installation of Boot Camp, creating Driver CD, and installing Windows. Purchase Windows XP w/Service Pak2, Vista, or Windows 7. There are presently several alternatives for running Windows on Intel Macs. If you really need to access such websites then you would have to run Windows on the Mac. All you can do in either Firefox or Safari is to change the User Agent to one of the IE choices, but that may not work for websites that require IE features that simply do not exist for Macs.