in regards to the hdd clicking problem, sometimes there is a 'normal' operating sound other times its a definate defect, which both 'click', however sound distinctively differently. To be sure, you can run the diagnostic application from the manufacturer of the hdd (free download from their websites) and also checkdisk if you want...
the uninstall problem, is it just with flight sim x? would other programs have the same problem or just that?
as stated above, there is the method of installing over the old one, and then uninstalling, or using the original install file and if it has the option when it loads to uninstall it directly.. failing that, you can try 3rd party removal programs like ccleaner and see if that works or the manual way to uninstall, which requires you to dig into the program files folder and registry.. something no-one that doesn't know what they're doing to perform by themselves..
probably the easiest method of manual removal is to delete (or move/rename it then reboot the pc to see if it has any effect as caution before you delete it) the game folder in the program files (wherever you installed it), then delete the shortcuts in start menu/desktop as well as any auto-loading startup apps related to it, then use ccleaner to clean up the rest. Although backing up is probably advisable still.
fyi, add/remove programs in vista is now titled "Programs and Features"...