Bash at the Beach Event: July 9th!
Dammit, I missed it all, slept through half and then ended up busy. :c
Woot! Did you get tickets or do I have to spend time with my boyfriend?
OK I'm also running in W10 so it should be installed under Program Files (x86)\Arc.
If it's not showing up in Control Panel (the real thing, not that useless POS called the Settings app), then you should be safe to straight up SHIFT-DEL the Arc program folder and reinstall.
As for the registry, you could launch REGEDT32.EXE and try going into HKEY CURRENT USER\Software\ and deleting the Cryptic and Perfect World Platform Client folders you should find there prior to launching the reinstall.
Of course if you're not comfortable hacking the registry, then DON'T. But if you choose to do what I listed above, make sure to reboot the PC before attempting the reinstall.