Educational software suffers from having been written many years ago, but the financial market is not such to give the publisher much incentive to update the software.
The problem for you is that Top Notch 2 with ActiveBook was written and released by Pearson back when Macs utilized the PowerPC CPU platform. In 2006, Apple migrated the Macs to Intel CPUs, but released their Operating Systems with an invisible translation program, Rosetta, so that the user could continue to use their existing library of PowerPC applications and take time to update them as needed.
The problem arises in that Apple no longer continues to update Rosetta for inclusion in Lion and now Mountain Lion, so that your CD-ROM cannot be executed on your Lion Mac.
Since Pearson looks unlikely to rewrite and release an Intel version of Top Notch 2, you must find a workaround that will play your CD-ROM and allow you to continue utilizing your ActiveBook.
You do not indicate which model of Mac you are using. If you upgraded it to Lion from Snow Leopard, you have these workarounds:
1. Revert to Snow Leopard
2. Partition your hard drive or add an external hard drive and install Snow Leopard into it. This will allow you to "dual-boot" into Snow Leopard when you need access to run Top Notch 2. You would then have to "dual-boot" back into Lion when you needed access to those features required by Lion.
If you purchased a new Mac that came with Lion, you only have one workaround available to run Top Notch 2:
3. Install Snow Leopard (with Rosetta) into Parallels
[click on image to enlarge]
There is an easier way to run your Top Notch 2 in Parallels if cost is not a significant factor for you. You must purchase Snow Leopard Server from a third party souce, such as eBay, which when sold by Apple was $499 or more. I now see that it can be purchased on eBay for as little as $51. Parallels allows for easy installation of Snow Leopard Server into Parallels.
If cost is a factor, then use the link above the photo to follow my instructions on how to install Snow Leopard client ($19.99 from Apple) into Parallels and achieve the same result.
Lastly, you could purchase a used Mac that will allow Snow Leopard to be the boot OS X installed (wth the optional Rosetta installed). But this seems like an expensive alternative just to run one piece of software; and subject to hardware failure without notice or recourse.
