Microsoft recommends the following minimum hardware to run Windows Vista Aero:
* 1 GHz 32-bit (x86) or 64-bit (x64) processor
* 1 GB (1 gigabyte) of memory
* graphics processor with minimum of 128 MB graphics memory, which supports DirectX 9, with a Windows Display Driver Model driver, Pixel Shader 2.0 in hardware, and 32 bits per pixel
For best results, follow these graphics memory recommendations:
* 64 MB of graphics memory to support a single monitor with a resolution that is less than 1,310,720 pixels (for example, a 17–inch flat panel LCD monitor that has a 1280 × 1024 resolution)
* 128 MB of graphics memory to support a single monitor with a resolution from 1,310,720 to 2,304,000 pixels (for example, a 21.1–inch flat panel LCD monitor that has up to a 1600 × 1200 resolution)
* 256 MB of graphics memory to support a single monitor with a resolution greater than 2,304,000 pixels (for example, a 30–inch wide-screen flat panel LCD monitor that has up to a 2560 × 1600 resolution)
if you meet those requirements, then maybe go to the theme and see if theres a windows aero theme