macbook "crashed"?

[blee0507]

hey i got a 2.0ghz white macbook about a week and a half ago, and up until now it was running great, without problems

but yesterday i was running a few apps like normal [limewire, firefox, adium] and my comp started getting reallly slow and laggy, and my istat pro widget suddenly disappeared when i installed bubble trouble widget.

so i decided to shut down my mac, give it a rest

and now i turned it on today to find ALL of my non-native apps and widgets [except limewire, firefox, photoshop, adium, app zapper, growl, strangely] simply gone. like, anything i saved, i.e account info, any app settings, plugins, scripts, downloads, all gone
ALL MY MUSIC IS GONE!!
how can 3700 songs disappear?
i know they have to be on my hd, memory left is still the same...

none of my system preferences settings have saved either,
all downloads such as firefox extentions nonexistent,
but all of my word docs/video files are perfectly fine.

anybody have any idea what happend to my mac?
is there anyway i can reverse this? [i'd hate to download everything again, it would mean a week's waste]
and how can i prevent something like this from happening again?

thanks

 

[lmcintyre]

simple, just click the time machine icon in the dock-- err thats not out yet. Honestly I dont know what could be the problem, just dont worry too much, theres lots of people on her who are experts.

 

[mad jew]

How much free space do you have? Have you renamed any of the system folders or your Home folder?

 

[clevin]

macfixit forum has a forum about a data recover software, u might want to check it out.