Installed Ubuntu Mate 16.04 but can't access windows 7 disk now

So I had to install ubuntu through uefi mode, standard mode wouldn't complete. Now I am unable to access my windows 7 partition on a separate drive. I have two SSDs in my system. A Crucial mx100 that holds Windows and a Kingston that holds Mate. Currently this isn't a big deal to me only because I'm just goofing off until fall semester starts but I do want to try to go ahead and get this fixed now before I go back. Any help is appreciated and I'll provide what info I can. Thanks in advance guys

How are you trying to access the drive is it from the Grub menu or though your bios usually you should access the drive through your bios and did you disconnect your windows partitions before you installed Linux on the separate drive.

Grub yeah. Worked with 14.04 just not sure why it didn't this time. All the stuff is still on the drive for windows

Think I might have got it working again just needed to update grub although that didn't seem to wanna work last time. Well here goes nothing

EDIT: We're in business. Strangely I have two windows 7 options. Thinking the other is just a duplicate

Did you accidentally install it with Legacy and not UEFI method? Windows uses UEFI, if you install Linux as legacy somewhere it will often wipe windows UEFI settings. You can recover it by changing Linux to UEFI (its just a partition and some files that you can do with a boot USB/disc)

Sorry forgot the partition boot assistance tool used to do it (under Linux).

No actually I did use UEFI but I just updated grub and it found it and just removed the extra boot option from the menu. So all seems to be well now. Just strange because I've done so many dual boot/dual drive installations but have never had this happen before

Always happens to me, especially with Ubuntu-based distros. Have to run GRUB twice.
The command in question is:

sudo update-grub

On Arch Linux it's:

grub-mkconfig -o /boot/grub/grub.cfg

(Just posting if someone else has same problem)

https://help.ubuntu.com/community/Boot-Repair try this tool, it saved me several times when I dual booted windows
Boot with the live USB, install it following the instructions and you'll get both working properly in less than 10 minutes.

Another tip, disable fastboot on windows and instead of "restart" use "shutdown" on windows to be able to access NTFS partitions from ubuntu, otherwise it'll complain about NTFS being in an unsafe state.