Hi Alfoil

Thank you for your long post, very informative.
I think your problems my be due to this:
Card name: NVIDIA GeForce 6100 nForce 405
Manufacturer: NVIDIA
Chip type: GeForce 6100 nForce 405
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_03D1&SUBSYS_D0001458&REV_A2
Display Memory: 256.0 MB
Even if this card have 256 MB,I'm not sure BM2 or BM 3 will play this game:
This is, I think, due to this:
The term GeForce 6100/6150 actually refers to an nForce4-based motherboard with an integrated NV44 core, as opposed to a standalone graphics card.
Taken from this:
In late 2005 Nvidia introduced a new member to the GeForce family, the 6100 series, also known as C51. The term GeForce 6100/6150 actually refers to an nForce4-based motherboard with an integrated NV44 core, as opposed to a standalone graphics card. Nvidia released this product both to follow up its immensely popular GeForce4 MX based nForce and nForce2 boards and to compete with ATI's RS480/482 and Intel's GMA 900/950 in the integrated graphics space. The 6100 series is very competitive, usually tying with or just edging out the ATI products in most benchmarks.
source:
http://en.wikipedia.org/wiki/GeForce_6_Series#GeForce_6100_and_6150_series_chip_specificationsIf it's not the above, it could be a) you'll need to update your directx, b) need to your update your drivers c) need to update your sound card drivers, or d) need to update the RAM in your computer. I have this game, and while 256 MB RAM is recommended, for Windows XP, they recommend 512 MB and for Vista and Windows 7 (I'd guess?),they recommend 1GB of RAM.
As you have 3008MB(=3GB) of RAM, this shouldn't be a problem.
The good news is that this model can be upgraded:
Info found here:
http://www.gigabyte.lv/products/page/mb/ga-m61sme-s2_2x/As you can see if you look at where it says 'expansion slots', you have, or rather the computer has:
1.1 x PCI Express x16
2.1 x PCI Express x1
3.2 x PCI
This means that you can get a better videocard, if you can afford one, of course. I'm not that tech savy so maybe some others will advice on which card is the best for you.
If you decide to upgrade, then please tell us if you mainly adventure games.
/Karsten