Create Desktop Mock up client Windows

General information for the business: Create Desktop Mock up client Windows (and Mac if possible)
Kind of development: New program from scratch
Description of requirements/functionality: Our software engineer has been poached by a competitor and has left us with a number of problems. We are weeks away from demoing our services and don’t have time to source another engineer, retrain and continue with the project.

So we need someone to create a dummy mock-up of our desktop application for it run on Windows 7 and 8.1.

A full brief will be provided to interested parties, however in brief the requirements are as follows;
- System try icon, right clickable with menu
- System try icon with occasional activity (spinning wheel/cog) with hover over Status label
- .exe Presence in Task Manager
- Windows folder with branded icon – like dropbox
- A main client with defined GUI screens, to be used for promo screenshots

Content, logos/branding etc. will be provided.

We need a quick turnaround for this, circa a week.

You will be expected to sign a non-disclosure agreement.

Don't know how much this would cost so please quote.
OS requirements: Windows, Mac OS
Extra notes: Mac OS version would be useful too but depends on cost.