How to erase the history in the built-in browser in MyEclipse

Access records for the eclipse's built-in browser are stored in the corresponding project directory. Metadata configuration,
That means you don't have to build a new project.

If you really want to delete it, find the Org.eclipse.ui.browser.prefs file in the workspace, for example, my workspace is D:\rapin
Then the file is located at:
D:\rapin\.metadata\.plugins\org.eclipse.core.runtime\.settings\org.eclipse.ui.browser.prefs

Empty the Internalwebbrowserhistory value inside the file

How to erase the history in the built-in browser in MyEclipse