phpmyadmin: Not functioning. Problem with mcrypt?

Just configured a fresh dev environment on an XP laptop. Am really jones'ing to configure a Linux laptop. Alas, I don't currently have the resources to acquire said laptop.

The "Welcome to phpMyAdmin" screen displays. Also displayed on this page is a box with a red outline containing the text "Cannot load mycrypt extension. Please check you PHP configuration."

Searching the web for that error message produces a lot of ancient postings, and a lot of different opinions. Information on this topic is certainly not evident if it is contained in the Documentation.txt file, provided with the phpMyAdmin distribution.

The configuration

• XP SP3
• Apache 2.2
• MySQL 5.1
• phpMyAdmin 3.1.3
• PHP 5.2
• Ruby & Rails
  
• X86, 32 bit Intel CPU & OS

Looking for hints and coaching ...