Mac OS X:
Mac Intel / 1GB of RAM / 30MB of Hard Drive Space
Windows XP SP 1 or later / Windows Vista 32-bit & 64-bit / Windows 7 32-bit or 64-bit / Pentium 4 2.4 GHz or faster (or AMD equivalent) / 1 GB of RAM / 30 MB of Hard Drive space
Adobe Premiere CS3, CS4, CS5
Adobe After Effects CS3, CS4, CS5
Apple Final Cut Pro 7, FCP 6, 5.1.4
Apple Motion: 3.02, 4
Avid Xpress Pro/Media Composer 5.6, 2.6, 2.7
512 MB of Dedicated VRAM
Since Magic Bullet Looks 1 is no longer updated/maintained, if it's running a host or operating system outside of these specifications, the program will not be guaranteed to work as it's technically in an unsupported environment.
See the compatibility page for the latest version of Looks to see what its upgraded version will work with.