When iam trying to deploy an event receiver to sharepoint web application i am getting the error “SpUserCodev4” cannot run on your computer.
From Central Admin->Security-> Configure Service Account I selected the Windows Service – Microsoft SharePoint Foundation Sandboxed Code option from the drop down and added my newly registered account (Lets say SP2010_Sandbox).
You must change the service account assigned to the service before starting the Sandboxed Code Service (This makes life a lot easier!)
After configuring the service account for Sandbox I navigated to Central Admin->Application Management->Manage Services on Server and started the service. From here everything looks fine and the service indicates started.