Microsoft discontinued Windows 7 gadgets in 2012 or so: https://support.microsoft.com/en-us/windows/gadgets-have-been-discontinued-0ef81ec8-e3cd-41d9-d129-c74e91d91d0b and https://docs.microsoft.com/en-us/security-updates/SecurityAdvisories/2013/2719662?redirectedfrom=MSDN
There may be third-party gadgets (or "widgets") that do work with Windows 7, but support for them does get pulled from time to time. The error message you quote seems to suggest that whatever online service that has been supplying stock prices to you is not functioning. That may or may not be permanent.
Which stock gadget do you have and when was the last time it worked?