Oh Dear - lost all files. Please help

[Leydeno]

I double clicked the HD file on the desktop. I then changed the name of the file on the left that has the house logo (I right clicked then chose the rename option and typed in a new name). This seemed to change my old settings, so I restarted the computer. This seemed to delete all my music files, all my photos, any applications that I've downloaded etc.

Could anyone please help me put the computer back to the moment before I changed the name of this file, or help me restore all my old settings and find my files! PLEASE! Thanks for your help.

I have an iMac G5 by the way

 

[iMeowbot]

how to fix: http://docs.info.apple.com/article.html?artnum=107854

 

[Leydeno]

Thanks for that. I'll give it a go