Parallels Desktop for Mac is the most tested, trusted and talked-about solution for running Windows applications on your Mac - without rebooting.
Parallels Desktop 9 for Mac delivers all this and more:
New! PowerNap extends to Windows and Windows applications so you're always up to date
New! Mountain Lion Dictionary gesture works in Windows applications
New! Connect Thunderbolt and Firewire devices to either your Mac or your virtual machine just like you do with USB devices
Enhanced! The New Virtual Machine wizard makes it even easier to create new virtual machines, automatically locating operating systems on your machine or letting you manually select a range of media types to install
More Information here: http://www.parallels.com/products/desktop/
Parallels 9 Activation:
1. Erase any parallels that has been installed before
2. Install parallels 9 (Trail Version - So that you will get a trail key)
3. Go to Macintosh HD/Library/Preferences/Parallels
4. Open the file "licenses.xml" using e.g. TextEdit
5. Copy your "offline activation key" located in line 12 between
6. Go to https://activatepd.parallels.com/ and paste it on the 'Activation ID', then click 'Generate Confirmation Code'
7. Copy the output and paste it in the "licenses.xml" line 8 between and save it.
8. Enjoy parallels!