Workflow change field

i'd a specific workflow to build, and i used the workflow brought by SPD.
so when i wanted to update a 'Status' field in the list where the workflow will be executed upon, the field doesnt update.
i past days of searching out for make that work, but no solution for.
then i realise that maybe the requester must have the right to update if i want that his request will be updated too, here i switch to authorisation form into the list, gives the right to the requester to update their data, finally i tested the workflow.
the result was : Amazing because it worked.