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