I moved this from Community Help to SecurityCenter as a better spot for it.
I see you are running XP. Note that Microsoft no longer support it & McAfee support for that will be dropped next year so you should start thinking about upgrading.
1st thing to try would be to run the Virtual Technician to see if it finds and fixes problems: http://mvt.mcafee.com/
If that fails to help try completely uninstalling McAfee via Control Panel > Add or Remove Programs
Run the MCPR cleanup tool, reboot and then go to your online account and reinstall from there.
If that fails to cure the situation, contact Technical Support by phone or online chat, it's free of charge.
http://service.mcafee.com/ adjust Country at top right if needed.
Regardless of the operating system there is a problem in McSvHost.exe as is apparent from the message in the first screenshot, which shows that mcsvhost was apparently attempting to write to a read-only portion of memory. In fact the memory address was 0x0, so this is a null-pointer deferencing operation, which will (almost) always result in an Access Violation. That is a coding bug which should be fixed.
Edit : It would have been even more helpful if some of the screenshots had shown the results of clicking either on the Debug button (which is an option I haven't seen before on this type of error dialog) or on the "click here" option, which would have provided some potentially useful technical info about the crash. Since McAfee creates log files all over the place it is possible that some information about the crashes is in one or more of these log files, although in the case of a sudden application crash the program may have terminated before the relevant information could be written. Still, they're worth looking at for clues.
Dereferencing just means reading the memory value at a given address. So when you have a pointer to something, to dereference the pointer means to read or write the data that the pointer points to.
A null pointer is a pointer that does not point to any valid data (but it is not the only such pointer). The C standard says that it is undefined behavior to dereference a null pointer. This means that absolutely anything could happen: the program could crash, it could continue working silently, or it could erase your hard drive (although that's rather unlikely).
In most implementations, you will get a "segmentation fault" or "access violation" if you try to do so, which will almost always result in your program being terminated by the operating system.