Question I need a best partition manager software for PC Windows 11

[synthia]

Hello everyone, I have a partition question. I have three hard drives: a 1TB old drive (which has data in it and is no longer used as a boot drive), a 64GB SSD new boot drive, and a 140GB spare drive. I want to divide the 1TB drive into two partitions, one for important files and one for the system, but I can't use the unallocated space when using tools such as diskmgmt.msc. Is there any partition software recommended for Windows 11? Thank you!