Click File->Import... from the top level menu to open the New Import Wizard
Expand the folder labeled "General". Select the sub-item "Existing
Projects into Workspace".
Then click Next.
In this example, the "D:\sourceforge\pretools-2_0_0-src.zip" archive contains one project: preTools. Here we select the "preTools" project and click Finish to initiate the import.
Note that the preTools project is imported into current workspace at "D:\eclipse-ws\preTools".