Replace your graphics card, or if it's a laptop, get a better one. You can try running at the lowest possible resolution to see if it helps, but your video is obviously way, way too slow. Look at the list of what is named as no good.
PC MINIMUM System Requirements
OS = Windows XP SP3 / Windows Vista SP1 / Windows 7
Processor = 1.8GHz Intel Core 2 Duo or equivalent AMD CPU
Memory = 1 GB RAM for Windows XP / 2 GB RAM for Windows Vista and Windows 7
Hard Drive = 15 GB
DVD ROM = 1x Speed
Sound Card = DirectX 9.0c compatible
Direct X = DirectX 9.0c August 2008 (included)
Input = Keyboard / Mouse
Video Card = 256 MB (with Pixel Shader 3.0 support). Supported GPU Chips: NVIDIA GeForce 6800 or greater(**); ATI Radeon X1600 Pro or greater. Please note that NVIDIA GeForce G.205, G.210, 310, 7100, 7200, 7300, 7400, 7500, 8100, 8200, 8300, 8400, 9100, 9200, and 9300; ATI Radeon X1300, X1550, HD 2400, 3100, 3200, HD 3450, HD 3470, HD 4200, HD 4250, HD 4350, and (probably) HD 5450 are below minimum system requirements. Updates to your video and sound card drivers may be required. Intel and S3 video devices are not officially supported in Mass Effect 2.
(**)Two of the Geforce 6800s are worse than the next-lower Geforce game card, the 6600 GT, and should be avoided (6800 SE, 6800 XT).
Yours must be as bad as the worst of those, if you have that symptom.