If you want to create your own Workflows using SharePoint Designer you need to enable it inside Central Administration. If not enabled you will get the following error message:
User-defined workflows have been disabled by the SharePoint Administrator. User-defined workflows will be unable to run
Usually this option is enabled but might be turned off by a SharePoint administrator.
If you want to add a SharePoint Designer created workflow to a list you must be a list administrator which means you have "Manage List" or "Web Designer" permissions.
SharePoint Designer workflows run using the system account. Instead of having full rights to SharePoint like Visual Studio developed workflows, SharePoint Designer created workflows have trimmed down rights. The workflow runs with the rights of the user who started it.
How to enable user defined workflows in a SharePoint Web Application
Open Central Administration and go to Application Management where you can select to manage your web applications. Select your Web Application and click the General Settings tab to open the workflow settings.
A dialog opens where you can enable user defined workflows and workflow task notifications:
- User defined workflows are created by SharePoint Designer (or a different 3rd party tool) allowing you to create new workflows using existing building blocks.
- Task notifications allow you to notify people who don't have access to the site.
- If you work with an internal user on a document the task is assigned to the internal user and an e-mail is sent with a link to the task. If the user clicks the link he or she can request access which has to be granted manually by a site administrator.
- If you work on a document together with an external user not having access to the site or document, the task is assigned to the workflow owner. An e-mail is sent to the external user with the document attached. The external user can work with the document and complete the task by sending an e-mail back to the workflow owner.
- Please read the following article for more information since additional steps are required: Plan for workflow security and user management (SharePoint Server 2010)
Click OK to save your settings.