I have bought loads of different cd-roms for my little boy who's now nearly 5 and have encountered numerous problems, but this program is really good! We have experienced issues with the software from Dorling Kindersley, but these cd's run without problems, also on XP - the software must have been updated since the first review was posted.
The games are challenging enough to keep him interested, but still learning through play, so that he doesn't lose his patience as he has done with others. It was really important for me to find a way of helping him forwards with reading and writing, without him "realising it" as he hates "traditional learning" through copying letters etc and I think this is finally it!
If you like me have been searching for good software, let me recommend a couple of other ones: Learning ladder is excellent, The Jump ahead series seems good, but for now my boy finds it's too much learning and not enough play - hopefully he'll return to it later...
On the other hand Play & Learn could have been good if it had been a bit more structured, but unfortunately you have to start at the beginning every single time and there is no way of gauging progress, probably better for slightly younger children. Finally all Dorling Kindersley programs we have tried have seemed really good, but we have had nothing but problems with the software, due to system requirements etc and their technical support is absolutely horrendous, so I've felt obliged to stay well clear!
I will post this review on the individual titles as well, because I found it such a struggle to find recommendations whe we set out on the search for software, so appologies if you have already read this somewhere else!