Hard Disk Problem

When I ordered my computer around 2 1/2 months ago, I customized it to be a 80 gb HD @5400 rpm and in Macintosh HD it says that I have 34.8 gb available, however I have not used 40 gb on the HD and it is really bothering me that it says this! Please help!

are you up to date on all the software updates available for your computer? usually, finder isnt the best it accurately displaying amount of space available, it just doesnt update as it should, the space is most likely still there, but you can be for sure by using system profiler. its in the utilities folder, who knows, you could have been given the wrong size drive.