I have a second harddrive on my system which always mounted at startup.

It had an old operrating system on it which which got in the way at boot time so I reformated the disk and now it can't be seen.

How do I re-mount it?

Can you give us more information like which fs did you put on it, does gparted see it, have you unplugged it and plugged it back in again. Can you post the dmesg output after having done that? Also check your settings in systemsettings - removable devices

Toad, thank you, I partitioned the drive then ran "sudo mount /dev/sda1 /mnt".

Result, the drive is mounted. Now I'm wondering if it'll mount next reboot.

No, I didn't disconnect then reconnect the drive.

Bill

for it to be mounted at boot you need to add it to /etc/fstab see https://help.ubuntu.com/community/Autom ... ide_Mounts

if you need added help provide type of partition (ext3, ntfs, etc....)