First Steps
You can install KOSMA on your Windows PC and start it.
You need a PC with Windows 10 or later and a KOSMA account. If you do not have an account yet, see [create your KOSMA account](/kb/article/create-your-kosma-account). On a Mac, see [install KOSMA on a Mac](/kb/article/install-kosma).
Open [kosma.io/download](https://kosma.io/download) in your browser and click **Download for Windows**. Your browser saves the file `KOSMA-installer.exe`. Most browsers save it in your Downloads folder.
Double-click `KOSMA-installer.exe`. The installer is available in English only, whatever language your Windows uses. Tick **I agree to the End-User License Agreement** and click **Install**. You do not need administrator rights for this. On the last page of the installer, click **Close**.
Open KOSMA from the Windows Start menu.
Click **Sign in with browser**. KOSMA opens the sign-in page in your browser. The steps on that page are in [log in to KOSMA](/kb/article/log-in-to-kosma). After you have signed in, KOSMA opens the Project Manager.
Install KOSMA on the second computer and sign in with the same account. The projects you have uploaded to the server are available there too.
When you sign in on the second computer, KOSMA saves your work on the first computer and signs you out there.
To learn how KOSMA saves your projects, see [how your work is saved and synced](/kb/article/how-your-work-is-saved-and-synced).
**If Windows warns you before the installer opens.** The installer has no digital signature. In the warning, click the link for more information, then the button that runs the file anyway. Windows then opens the installer.
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