Bitcoin Forum

What is the latest version supported by Windows 7?

Idk, but you should not use Bitcoin on no longer supported (insecure) software.

--Knight Hider

Any electrum version before 4.2.0
The last compatible version of electrum on windows 7 was the 4.1.5. The best thing is to actually upgrade your operating system because even windows have actually ended support for this window 7.
The new electrum version 4.4.5 is said to be compatible with windows 8.1 according to there support (https://electrum.org/#download)

Here is also a electrum release notes on GitHub (https://github.com/spesmilo/electrum/blob/master/RELEASE-NOTES)

This is not advisable since windows 8.1 and above is the recommended OS to use for electrum wallet and using old version might exposed you some risk since some of Electrum updates might be related to issues found on old version.

You can use this thread https://bitcointalk.org/index.php?topic=5391269.0 as reference to your concern.

Version 4.1.5 is the last version supported by Windows 7 as per @Charles-tim thread https://bitcointalk.org/index.php?topic=5391269.msg59633634#msg59633634

You have already received your answer, but I would like to strongly encourage you to seriously consider upgrading your operating system. Microsoft ditched support for Windows 7 a long time ago. That means no new patches or security fixes, leaving your system vulnerable to potential attacks whenever a new vulnerability is discovered. If your hardware cannot handle newer Windows versions, I recommend migrating to a Linux OS. It works well on older hardware, receives regular updates, and is generally less susceptible to security threats.