Hi,
MagicInfo I is now known as MagicInfo I Premium and is free to a point (basically the first 5 displays), also the interface is different to MagicInfo I - as a company we have been involved closely with Samsung when they first launched MagicInfo I on the quiet sometime ago and have deployed it on numerous educational and corporate sites.
MagicInfo I is no longer a supported product, nor available from Samsungs download site (I just checked), so it would need to be MagicInfo I Premium.
Thinking about your ppt issue, do you have ppt viewer installed in each screen? the screens from samsung are shipped 'dumb' so you need to install codecs depending on the content you are going to publish.
Another option, although a pay for option is signagelive (digital signage software | signagelive delivering media to your screens) which is 'cloud' based and which offers a couple of options depending on your content requirements. They also do an upgrade path for existing MagicInfo users and it works great with the Samsung displays.
If you need any extra info, just ask.
Simon