Lost data

[Erlend Clouston]

Greetings! Part of a very important file I was working on this evening 
has vanished. (The other part remains visible.) A techie friend 
speculates that I may have accidentally highlighted and then deleted the 
vanished section. He says not to worry, as "it will be somewhere on your 
hard disc." Hmm. Is there any simple way for a non-techie to test his 
thesis?
Thanks for any simple advice.

- Erlend