The raspberry pi is a good suggestion, but if you don't want to be seen bringing outside hardware into the building, you could look into Amazon Workspaces or an

The raspberry pi is a good suggestion, but if you don't want to be seen bringing outside hardware into the building, you could look into Amazon Workspaces or another remote workstation service, or host your own box and remote into it. Workspaces has a web client for accessing your workspace, so unless Amazon cloud services is specifically blocked at work, you should be able to access it. There's a small monthly fee, but I'd think it'd be well worth it.