Legally... yes, well maybe. First, even with Bart's PEBuilder, you need to own a dedicated WinXP license to build the bootable CD from...
Next, you need to assemble all the stuff yourself (it's more or less like a box of bricks) - in contrary to avast BART CD where you have all the pieces assembled automatically... Next, Bart's PeBuilder comes with no technical support which is IMHO quite important for such a tool...
Overall, we believe that for commercial-grade users / computer professionals, our BART CD, despite its price, is still a very good deal.
And with version 2 (coming soon), it's going to be even better.
Vlk