upgrade small windows service VS2005 to VS2019 made in C++

this is a test for a C++ expert. ve have a solution/system written in C++ 2005 that is composed by several windows services. we need an C++ coder that in first instance takes 1 of these services and makes them compile in VS2019 (and of course the service needs to run and work as if it was compiled in VS2005). the project that we will deliver for upgrading works if its compiled in VS2005, if the code is compiled in VS2019 it compiles but it does not run as a service as it should. so this is a small upgrading test to see if the person can upgrade the rest of the source code so everything compiles in VS2019 which is what we really wan at the end