<human>: Can you provide a brief rundown of the text in within 3 sentences?

First things first, I am working in a computer company.
We are having some other companies as customers. One of these companies is still running Windows XP (support for this operating system endet in April 2014) on some few of their PCs. Because of a security exeption they were able to use it so long after end-of-support, but need to change to Windows 7 until 28th of February.

So I am the guy reinstalling all those PCs with Windows 7. And up until now, nothing really bad had ever happend. We got this checklist so we can test, if all the programs are working.
As I said, until now nothing bad happened so I started to just check one (out of like 20-30) programs because it took a lot less time for me to do that. Also you need to know if one is working the others are working 99% sure too.

We need to show the users the basics of the new operating system and because i am comming later to work tomorrow i asked a coworker to do that for me. I told him I checked everything with our test user and he should have no trouble tomorrow. Of course I didn't check anying because it was around 4 pm and I was about to go home (and also because as I said I never recently had any troubles with any program).

Then about ten minutes later he texts me in our group chat with my other coworkers and my boss (!) in it if I was sure I checked the PC. I was confident it could nothing go wrong with my plan so i responded "Yes I am. Why?".

What comes next is the real FU:
He sent a picture of our PC management software where you can see what user last logged onto that PC. Obviously there was no last user because I didn't log me in.
What came after was a combination of my nickname and liar from some of my coworkers. My boss also wasn't that happy about it.
I really don't want to go to work tomorrow... At least I can sleep a little longer tomorrow, im on my way to a bar right now. I need one or some beer with friends.
<bot>: Lied to my coworker, he found out i lied and now my whole team including my boss knows about it and I don't know what to expect for tomorrow :(