Hi, I think Virtualization might be the only way, but is it a Core Duo, or Core 2 Dou model?
At the Apple Icon at top left>About this Mac.
Then click on More Info>Hardware and report this upto but not including the Serial#...
Hardware Overview:
Model Name: iMac
Model Identifier: iMac7,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 6 GB
Bus Speed: 800 MHz
Boot ROM Version: IM71.007A.B03
SMC Version (system): 1.21f4