(banking, work documents, personal IDs), seriously consider upgrading to Windows 10 or Linux. You can run Windows 7 in a virtual machine for Messenger only.
Before proceeding, ensure your machine meets these minimum specifications: Facebook Messenger For Windows 7 32 Bit
Several open-source developers have created wrappers that package the Messenger web interface into a standalone application. One of the most famous for legacy systems is (also known as messenger-desktop ). Facebook Messenger For Windows 7 32 Bit
The most secure and updated way to use Messenger on Windows 7 is through a web browser. Facebook Messenger For Windows 7 32 Bit