Tell me what files do you see in InfinityMU Client/MuGuard folder or just take screenshot of the files in MuGuard folder.
Try this for now:
Right click on My Computer then Properties then Advanced tab > Performance Settings > Data Execution Prevention > Turn on DEP for all programs and services except those I select > Add... > the add mu.exe and main.exe which is in our client root folder then click Apply and then OK. Try to connect and if still not work, try to restart your PC.