Here are my parameters:

- Access Database drive sites (file size around 5Mb)
- Around 20 users simultaneus per site.
- Average file size is 500kb

(500 * 20 / 1024) = 9,5 Mb Ram usage per site

If have 512Mb of Ram <-------------------> (512 / 9,5) = 50 sites


- I planned host around 20 sites


With:

PowerVPS (Windows soltution)
WINDOWS POWER-2
- 512MB RAM guaranteed
- 10GB Disk Space
- 250GB Monthly Transfer

Is enought?

Other questions:

- How calculate ram usage for a database? like filesize or recordset size?
- Can plesk manage asp components?

Thanks