While installing a fresh Magento installation, some users are stuck at the 'Create Admin Account' step, with this error: 'Password must include both numeric and alphabetic characters.'. Follow this simple step to resolve this issue.
The reason for this error is in the following code in the file app/code/core/Mage/Admin/Model/User.php
if (!preg_match(’/[a-z]/iu’, $this->getNewPassword())
|| !preg_match(’/[0-9]/u’, $this->getNewPassword())
$errors = Mage::helper(’adminhtml’)->__(’Password must include both numeric and alphabetic characters.’);
The preg_match() function is the culprit. It fails because the PCRE extenion in perl is not installed properly. This can be easily resolved by running the following command in your linux
yum install pcre
#if yum doesn't work use apt-get (depends on your linux variant)