My 06' Macbook Pro crashed with vertical, green pixelated lines and now will not advance past the turn-on screen with the apple filled with green lines as well. Then, it says to hold down the power button to restart. Help?

My 06' Macbook Pro crashed with vertical, green pixelated lines and now will not advance past the turn-on screen with the apple filled with green lines as well. Then, it says to hold down the power button to restart. I have tried several times to get it past this point but tnothing helped.

I have an appointment at the Apple store today, but was wondering : will all of the information and files on my desktop be lost? Or is this a logic board problem?

Any help is much MUCH appricated.