# Install and sign in

> Get the Calc add-in into Excel, sign in, and understand seats and sessions.

Calc installs into desktop Excel and adds a **Calc tab** to the ribbon. New
versions are released regularly, and Calc prompts you to update when one is
available - so you stay current as the product evolves.

## Requirements

- **Windows** with **desktop Microsoft Excel** (the add-in is Windows-only).
- A **GIMLabs account** at a company with an active subscription. Calc is
  included on **every plan** - on **Go** you can collect data, and **Pro** adds
  template building. If you cannot sign in, your company administrator manages
  access.

## Installing

You download Calc from **Product OS**, the GIMLabs web dashboard.

<Steps>
  <Step title="Open Product OS">
    Sign in at [os.gimlabs.io](https://os.gimlabs.io). The dashboard shows a card
    for each product your company has access to.
  </Step>
  <Step title="Download Calc">
    On the **Calc** card, click **Download** to get the Windows installer.
  </Step>
  <Step title="Run the installer">
    Run it once. The **Calc tab** then appears in Excel's ribbon every time you
    open the application.
  </Step>
</Steps>

<Callout type="note" title="New versions are released regularly">
  Calc checks its version when you sign in. When a newer version is available
  you will be prompted to install it - sometimes optionally, sometimes before
  you can continue. See [version updates](#version-updates) below.
</Callout>

## Signing in

<Steps>
  <Step title="Open the Calc tab">
    In Excel, switch to the **Calc** tab on the ribbon and click **Log in**.
  </Step>
  <Step title="Enter your details">
    Sign in with your GIMLabs email and password in the dialog that appears.
  </Step>
  <Step title="You are in">
    The ribbon updates to show **Projects** and **Templates**. You are ready to
    [pick a project](/calc/collecting-data).
  </Step>
</Steps>

<Callout type="warning" title="Sign-in problems">
  "Incorrect email or password" means the credentials did not match. Sign-in is
  also refused if your account is not active, your email is not verified, your
  company's subscription is inactive, or you are already signed in on another
  account. See [Troubleshooting](/calc/troubleshooting).
</Callout>

## Seats and sessions

- Your access comes from your company's **subscription** (Go or Pro) - Calc is
  included on both. Each active user takes a **seat** under that plan.
- A **session** is your current signed-in use of Calc. Administrators can **end
  a session remotely** - for example to free a seat. If that happens, Calc signs
  you out with a notice; Excel stays open and you can sign in again.

## Version updates

When you sign in, Calc compares its version with the latest:

- **Optional update** - you see a dismissible notice and can carry on, then
  update when convenient.
- **Required update** - sign-in is blocked until you update. The notice links to
  the new version to download.

## Signing out

Click **Log out** on the Calc tab. Your session ends and the ribbon returns to
its signed-out state. Your workbook stays open and untouched.