What is the scheduled task "\Microsoft\Windows\CertificateServicesClient\UserTask-Roam" on my Windows 8 computer?

"\Microsoft\Windows\CertificateServicesClient\UserTask-Roam" is a scheduled task on Windows 8 system added as part of Windows installation.

You will see "\Microsoft\Windows\CertificateServicesClient\UserTask-Roam" listed on Task Scheduler with the following information:

Name: UserTask-Roam
Location: \Microsoft\Windows\CertificateServicesClient
Description: Certificate Services Client automatically manages 
   digital identities such as Certificates, Keys and Credentials for 
   he users and the machine, enabling enrollment, roaming and other services.
Actions: Custom handler
Triggers: On workstation lock or unlock of any user
History:

"UserTask-Roam" is scheduled to run when system is locked or unlocked. It is disabled by default.

It is recommended to disable "\Microsoft\Windows\CertificateServicesClient\UserTask-Roam" as a scheduled task.

⇒System Scheduled Tasks on Windows 8

⇒⇒Windows 8 Scheduled Tasks