D-Fend Reloaded is a graphical environment for DOSBox. DOSBox emulates a complete computer including the DOS commandline and allows to run nearly all old DOS based games on modern hardware with any of the newer Windows versions.
With DOSBox there is no need to worry about memory managers or free conventional RAM, but the setup of DOSBox is still a bit complicated. The configuration of DOSBox via textbased setup files might be difficult for beginners. D-Fend Reloaded may help and create these files for you. Additionally the D-Fend Reloaded installation package contains DOSBox (including all lanuage files currently available), so there is only one installation to be run and no need to link D-Fend Reloaded with DOSBox manually.
Author's page below has several preconfigured game packages available for free download.