Photoshop and amtlib.dll

Hello,

I am a design student and I am using Photoshop CS6. I have a project due this week, so I can't afford to be without it, and I have a first submission to make tomorrow.
I don't know anything about computers, all my settings are done by my roommate who is currently unavailable (so please be patient and explain things to me in a very simple way).

My problem is as follows: for a while now, I haven't been able to open PS. An error message appears (with the characteristic "tinlin" of bad things on Windows) telling me that PS cannot be opened because the amtlib.dll is missing from my computer, and that I need to reinstall the program. However, I don't have time for that because my computer is slow, and I'm also afraid of making a mistake or something that would completely block my access to Photoshop. In desperation, I did some research online and saw that it is easy to download and replace this amtlib.dll (well, easy depends on who you ask). Most of the answers I found are in English, and English + technical language = completely indecipherable language for me. I downloaded a file that installed itself and then brought me back to the download page, without any file I could use to replace the one that got damaged...

Could someone help me? I would be eternally grateful, because I'm considering throwing my computer out the window which would greatly ease my nerves.

Thank you so much!