Unistall Parallels Windows 8 Bootcamp Partition

I got a trail version of Parallels 8, isnatlled the software. Selected to use my existing Windows 8 virtual machine. Everytime I tried to load the virtual machine it would stay on converting partition for about 5 mins then when the VM loaded it would be slow and almost unusable, despite having 4gb RAM and 4 CPU allocated. When I log into bootcamp it would freeze at the Windows 8 statrt menu for about a minute then would load the start menu again. Programs such as chrome no longer open, steam cannot download anything and god knows what else is now broken!

I have deleted the VM from the menu in OSX, but the problems still persist in bootcamp. The only remaining file containing any reference to Parallels is in C:Bootcamp TEMP_PARALLELS_TOOLS and contains 1 file PTIAgent which I cannot delete even running admin as it says "An unexpected error is keeping you from deleting this file". Nothing to do with Parallels in Add o Remove programs either.

Any sugestions as to what I can do now as my bootcamp partiition is now UNUSABLE!