Kasey,

If the error is mentioning the test_type.cab file, this was corrected in patch 8 of Quality Center. This file had a digital signature and the signing key expired in December 2009 causing the error. HP promptly released patch 8 to correct the issue.

Generally, to receive patches and updates you must be covered by support for your HP products. I would recommend checking the site you downloaded the trial from to determine if there is any HP provided contact information to receive the patch for your trial period.