hi everyone, i've lost double h in east wing and without him I can't go out (i need him to help me keeping off electricity) and come back to the surveillance room, where I still have to take last photo
please help me or I'll have to start again
serenA

I assume you have no savegames left where Double H is still with you? First of all, in case you can't continue at all there are a few savegames available in this thread:

http://forums.ubi.com/eve/forums/a/tpc/f/401101532/m/954104004

Secondly, you could try the BGAEFix tool created by rahly (if you have the patched version of the game):

http://www.terrygoodkind.net/%7Erahly/bgae.php

Put the executable in the BG&E directory (the one containing the .sav files) and start it, then select the savegame where Double H is gone and click "Double H Fix" (you might want to make a backup of all the .sav files and the sally.idx file before you try this). I've never tried that fix so I'm not sure if it always works but it's worth a try.