First of all, a little late, but you should not be editing the profile in /etc (or anything else in that directory if you're not sure of what you're doing). You should make changes like that in your home directory, to the file ".profile". Then, if you mess up, it's easier to fix, and if you ever have more than one user, it won't affect all users.
Next, thing is that you need to be careful with spaces for any linux command. Spaces are what separates parts of the command, so if you actually have a space in your path or filename, you need to either use double-quotes, or a backslash in front of the space, like this:
file\ name\ with\ spaces. This is called "escaping the space".
To fix your problem, you will probably need to boot from a live CD, either the original or a repair disk. Once booted, you can find your installation on the hard drive, change to the /etc directory, and edit the file, preferably by removing your changes and making them correctly in your home directory.
Edit: Fixing the problem when using wubi
I've never used wubi myself, but there are ways to access the partition either from Windows, or from a live CD or linux utility CD. There are details in the Ubuntu WubiGuide, but here is the basic from that guide (untested by me):
Boot the Ubuntu Desktop CD, or another LiveCD, then mount the windows partition:
sudo mkdir /win
sudo mount /dev/sda1 /win
Replace sda1 with the appropriate device (a = disk, 1 = partition number), then mount the virtual disk therein
sudo mkdir /vdisk
sudo mount -o loop /win/ubuntu/disks/root.disk /vdisk
Now the content of the virtual disk will be visible under /vdisk. 7.04 users will have to install ntfs-3g first and specify it as fstype to gain r/w access.