I don't use partition magic so can't be specific but I would think that you need to use it again to expand your C: partition to include the unallocated space left from deleting the 50GB partition. Windows XP can't do this unaided.
OnePlus 5 review
Alice Saey's mesmerising animation for Dutch singer Mark Lotterman
iPad Pro 10.5in (2017) review
Comment faire une capture d’écran sur un Mac ?