Here're NTFS and FAT32 file system resources, you can find guides and solutions on how to convert NTFS to FAT32 without losing data or formatting.
Wipe single file on the disk is easy, but wipe files on one partition can be troublesome in file erase software. Try Data Wiper to wipe entire partition with ease, with or without bootable media.
Windows Server 2008 R2 Disk management has more functions than Windows 2003, Extend Volume and Shrink Volume are possible now, but still not a powerful system utility to manage disk space with ease .
Here're some resources about Windows 10 problems, maybe they might be some help when you're running out space on C Drive or low disk space alert keeps warning you. Besides, there're also solutions on Windows 10 errors for users who have upgraded from Windows 7 or 8.