Cannot extend c:\win on dualboot as no unallocated space nextdoor partition, extend is greyed out on disk mgt,

My dual boot windows c: has only 2 Gb left and no unallocated space nextdoor parttn. Disk mgt C: has 'extend volume' greyed out obv. Sorry newbie mistake i did query for similar threads but thought to check with u guys first as would hate to lose possibly Ubuntu exten parttn nextdoor to it(to right)... Ubuntu installer created (the previously massive, empty parttn i created nextdoor) this parttn as a container for its extended parttns for itself to be in. It (this nextdoor parttn) is 200 GB, i mistakenly made it massive, and with nothing else on it,prior to Ubuntu installtn. df -L shows it as just havg dos/mbr reference at top, with "bootstrap BOOTMGR" at bottom(assume all exten. parttns have this in them?).Just ntfs, otherwise empty. Shall i go ahead & use third party parttning software? As per, the only unallocated space is end of disk, linux's friendly 1.1Mb. No other unallocated anywhere, total newbie bloop!