Laulajatar: I hardly believe the computer is to weak - being 10 hours into this game without the slightest performance problem and then dropping from perfect to unplayable just because the rain starts.
Problem is, you can't turn particles off! Just "low" and that doesn't help at all.
Intel Dual Core somewhat over 2GHz, 4 GB RAM, Win7 64 bit aaaand I think it was GeForce 310M.
The other computer is Intel 2,6 GHz Dual Core, 3 Gig RAM, Radeon HD 4870 1GB RAM graphics card, Win XP. Skyrim, Deus EX HR, Fallout, Two Worlds II, all of them run without a problem here. I can't play Bard's Tale at all.
I believe for nVidia cards it's a problem with Win 7 systems which only acffects particles.
As for the Radeon card I think I read something about the game using a shader model (1?), that this new graphics card doesn't support anymore. I'm not sure if there is anything at all that could be done about this.
BTW, turns out that the steam version is the updated i0S version of the game. With the Apple IIgs emulator included, rather than the DOS versions of the games.
Ok, many if not most laptops with Nvidia also share the systems with an integrated intel card.
Make sure if you have Nvidia and Intel Integrated combination setup, make sure you you go into your Nvidia Control Panel, and to Manage 3D settings, and make sure that The Bard's Tale is set to Nvidia, rather than "Integrated". Bard's tale likes to default to the Integrated chip, and its a pretty lousy for gaming.
I don't now much about the Nvidia 310 (it does look to be one of the lower-mid range chipsets of its generation,from what I can tell), it may not have enough power to handle high levels of particles/polys, however definitley make sure that the Intel Integrated isn't the problem. I have an Nvidia 540M on my system, which is more robust, so even if I was to get to your point it wouldn't be a proper comparision (it also has 8 gb of ram, which also would make it a not so equal comparison, although the CPU looks to be about the same, I have i7 dual core that boosts up to or 2gh or so from 1.5 IIRC).
Also, you can try to disable a core, and run it on a single core. There are a handful of games out there that dislike multicores. No telling how that will affect Bard's tale though. More than likely any multicore issues have been fixed by GOG or the publishers of the game already.
Make sure your video drivers are the most current and up to date. Use the newest beta versions at your own risk. Update any other drivers such as your bios, sound, etc, while you are at it.
Also check to see how much memory is being allocated to the video card, and dedicated video memory exists (this can't be changed, but the information can be useful).
You might also attempt to increase resources to the paging file. Sorry don't know how to do this in Win 7, and haven't bothered since my computer generally is pretty good at handling everything.
As I mentioned before make sure your power/battery settings are set to High Performance. It makes a difference even plugged in.
Other things, try to disable any useless background processes as possible. Maybe even disable steam while you are running it. This is to dedicate as many resources to the game as possible.
You might want to run a resource utility monitor, and see if the game is reacting in your system. This might show if there is a memory leak in the game or not, or if its pushign your CPU to max.
Other things to try, is keep your computer cool, using a cooking pad if you have one. Overheating can also have adverse effects.
I can't help you with the Radeon card issue however, all though I do think my other laptop is a similar machine with similar setup (same generation of card, but maybe slightly less powerful). I might check it out later, just to see if I can get it to load up.
Also is it possible for you to send a save game of the point in the game just before the problem arises so I can test it on my machines? I don't want to play for 10 hours to try to reinact your issues.