Playing games sent via e mail

​ I am a new user and admit I am not all that hot with technical issues on the computer so I apologise in advance if this seems dull! ​

​ ​

​ I have recently received a series of games such as Tetris, Pacman etc from a friend sent as e mail attachments - they are either pps or xls files. I have downloaded power point viewer and excel viewer. However when I try and open the attachments in Outlook Express it refuses saying that I do not have an associated programme! In my internet web address (yahoo browser) I can open the attachments but when I do I can only get to the first page of the game. It seems they are not interactive and as such I can't play the game. As soon as I hit a key in pps it goes straight to "end slide show"! In xls I again don't seem to have any interactive functions! It's just a basic spreadsheet with the picture that's the first page of the game but I can't het the start playing button or anything! ​

​ ​

​ I know that it's not a problem with the e mail attachments themself cos I forwarded the email to my office e mail and the games work fine when I open them on my works computer. ​

​ ​

​ Is there any other software I need to download to play the games on my home computer? ​