To correct myself a little bit, Microsoft certainly offers extended support for Windows 7 until 2020, but it appears to be tied to the service pack level that is currently being supported by the company. It does apply to business, developer, and desktop operating systems. I assume that Windows 7 Home Edition, for example, is covered under this (if you have the latest service pack?)
As to the company's providing security updates, notice the third bullet point from the top of the web page. It is all a bit iffy for their older operating systems, and Windows 7 certainly has gray hair. We must not expect clarity from Microsoft.
With the above noted: I agree entirely that if one wants to work with databases, it is absolutely essential to get on a 64 bit operating system. Select an operating system which is supported by the database vendor. There is plenty of choice these days, and Linux is a free operating system.
The other thing I would mention is that the original poster can check if the laptop in question has a 64-bit capable processor. Just about all processors today do have 64 bit support and Intel offers virtualization extensions as well. If the processor supports 64 bit, then just remove the current hard drive (with Windows 7 installed on it), slot in a brand new hard drive, and go right ahead and install Linux or 64 bit Windows 10. I think some products from MongoDB such as Charts are only supported on Windows 10.
Thanks so much
Bob