If, as r_maic asks, you do NOT want any information off those two drives, deleting the partitions on them and starting from bare empty drive status is the way to go. You may well be able to do this with Windows Disk Manager. Get there (if you don't know how, post here) and look at the right-hand lower pane showing all hardware devices, useable or not. RIGHT- click on a Partition of one of these drives and choose to Delete this Partition. Do that for every Partition you find on both drives.
This makes them empty drives (even if, technically, there is data in places, it cannot find any of it). For each you do two steps: create a Primary Partition of specified size (all of the drive, or less if you wish) and choose whether this will be a bootable drive / Partition, or not (just use to store data). Then you Format this Partition and I recommend you choose the NTFS file system unless you know you need FAT32 for a special reason. A Quick Format usually will do - it does all the formatting work in 5 to 15 minutes. A Full format adds a very long disk testing process - we did one the other day on a a 1.5 TB drive and it took 5 hours.
Once those two steps are done, reboot and let Windows find and use the drives. You should see them in My Computer.