Go ahead, and install Ubuntu now.
Yes, a week later the Win 7 upgrade WILL mess with your MBR/Grub/boot. But good news is: it WONT mess with your Ubuntu partition.
The point is: its SO easy to fix grub that you should not worry about this. Just follow these steps:
Before upgrading Windows (ie, while you still can boot Ubuntu):
Burn an Ubuntu bootable CD, or use the "Start Up Disk Creator" utility from Menu -> System -> Administration to create a bootable USB key. You probably already have either the CD or USB, the same you will use for installing Ubuntu works fine
Give your Ubuntu partition a label. Not necessary, but helps.
After upgrading Windows (to restore grub/Ubuntu):
- Boot using your CD/USB and start a Live session
- Got to Home Folder -> Computer, find your Ubuntu partition, and double-click to mount it. If you have trouble finding which is your Ubuntu partition, use
gParted. After mounting, take note of WHERE it was mounted (usually will be /media/LABEL, where LABEL is the Label of your Ubuntu partition, if it has one. Hence my previous suggestion on labeling it)
- Also, using gParted, take a note of of which device is your boot drive. It will probably be
Now for the "real deal deal":
sudo grub-install --root-directory=/media/UBUNTU /dev/sda
And thats it!
Reboot, and grub will show up, allowing you to use Ubuntu again
In these examples, i assumed you labeled your Ubuntu partition
UBUNTU, and your boot drive is
/dev/sda. Check those values before issuing the grub-install
After booting on Ubuntu, do a
sudo update-grub so it scans your drives again and add the Windows 7 partition to the list. It was there before, as Vista, but an update will fix menu name and other options
Dont worry about the error message: "cannot find /boot device. (is /dev mounted?)" while (re-) installing grub from Live CD. Its an annoying bug. If there is a message "All steps successfull" shows up, everything is fine.