Question: His favourite course during his first year had been calculus and its applications so since he had always enjoyed mathematics there was an obvious direction in which to take his studies
Please fix the punctuation.
Fixed: [His favourite course during his first year had been calculus and its applications so, since he had always enjoyed mathematics, there was an obvious direction in which to take his studies.]

Question: The vinyl roof is also new
Please fix the punctuation.
Fixed: [The vinyl roof is also new.]

Question: Program Modification Sometimes not only virus TrojanLinuxCalifaxA or malware HiPageDustman but also common softwares possessing the ability to modify the inner functions of conhostexe which means other programs cant find this DLL file again
Please fix the punctuation.
Fixed: [Program Modification: Sometimes, not only virus Trojan:Linux/Califax.A or malware Hi-PageDustman but also common softwares possessing the ability to modify the inner functions of conhost.exe, which means other programs can't find this DLL file again.]

Question: A good practice is to close all programs that are open before you run CurrPorts to limit the number of open ports to Windows processes and background applications
Please fix the punctuation.
Fixed:
[A good practice is to close all programs that are open before you run CurrPorts to limit the number of open ports to Windows processes and background applications.]