Offline means that the audio files are not available (they are deleted or on another hard drive location). This probably means that when you saved your project, you didn't tick "save project in its own folder" and "copy media items to project folder". You have those options on the bottom left of the save prompt. Resave your project with those options checked, and put your project folder on your USB stick, it should work then.

thanks Evil Dragon. i ticked the box for "copy all media into project directory" and that worked.........but.....on opening the project on my laptop, i found that the VST reverb effect i gave one of the tracks was missing. When I tried to put it back on (a default "sweet verb") I found that there were no VST effects available, only JS effects. the other boxes to tick in the Save As prompt were: "move all media into project directory" "create subdirectory for project" and "trim and convert" any ideas ??? thanks

You probably didn't copy your VST plugins and instruments to your laptop and that explains why they are missing. To keep it simple, copy the VSTs to the same location on your laptop as they are on your PC. Otherwise you'll have to change the default VST path in REAPER every time you switch from PC to laptop. Kind of a hassle. :)

Also, if you have a USB key with enough memory you can put a selection of your fav plugins in a folder on the USB key,( you,ll need to direct reapers vst path ( on the USB key )to this folder) that way you can plug into anyones computer and have everything you need to do a mix if you have to. Well, maybe a rough one ;) It works surprizingly well. Cheers

Yay ! done it...thanks for that. I HAD copied over all the reaper files but for some reason when i opened the FX file on my laptop it was....empty. go figure ?? thanks again

Yeah, you have to have all your VST effects installed to the SAME PLACE as on your desktop, to have your projects working. Either that, or you can put them anywhere, but then point Reaper to that location afterwards.