That report said you had a 30 day warranty on whatever they did, but the fact they say they also added some security things would make me suspicious - they weren't Microsoft Support techs - where did you get their phone number from and why did you contact them in the first place or was that the pop up you got to call their number.
It sounds as if you have fallen victim to a scam so under no circumstances do any online sensitive stuff on that computer.
This includes online banking or anything that requires you to use an username or password such as e-mails.
Did you find that Trojan after they affected the "repairs" ?
It's highly unlikely you will have any restore points to go back to before you let these guys loose on your machine as they probably deleted them, but you could check.
Are you able to boot up into the Advanced Boot options to select Safe Mode with Networking to see if the computer stays on then.
Depending upon the make of computer, tapping F8 as you switch on will bring those options up and you use the cursor keys to select whichever option then press enter.
You can then check to see what restore points you have, but fortunately, if the machine works in Safe Mode then you will be able to use the Windows Repair program.
If you can work in Safe Mode then click on Start - type msconfig and press enter.
Click on the Startup tab then on Disable all then click on the Services tab, check the box to Hide all Microsoft services and then click on Disable all - but you must hide all Microsoft services first before the Disable all.
Click Apply - OK then Restart now to see if it still shuts down in normal mode.
Depending upon which antivirus program you are using, as soon as you click on Apply, its box can auto recheck to reinstate itself so that is nothing to worry about, but if any other box also does that - then let us know.
While I haven't compared the status of all of your services to my Win 7 ones, the Credentials Manager is showing as Started and Manual on mine but stopped on yours.
This is a security service, so if you are able to use your computer in Safe Mode, go Start - type services.msc and press enter.
Scroll down to Credentials Manger, click on it and then on Start in the upper left pane to see if it will start.
What are you using to post on now ?