My Skyrim files have been moved?

So my laptop recently got a problem with the fan. So my mom gave it to a family friend of ours who knew how to fix it. The laptop fan would always be loud. Weeks later we got the laptop back, and a lot changed! I no longer had the Alpha Tango and my Guest acc, I only had this one acc with my mom's name on it. What was left was, I still had my Skyrim files but Skyrim was no longer installed (I think). I searched for Skyrim at the windows button and The Elder Scrolls Skyrim shortcut said it was either changed or moved. I scoured my laptop files for my skyrim folder and all the files were still there, including my saves and my nexusmods folder filled with mods. I want to play skyrim again. Can anyone help me?

Yes, as @Nzall said your best option would be to install Steam and Skyrim again on the new account. That's easy - the difficult part for you is getting the mods back.

Firstly, check where the current Skyrim files are. Steam usually installs games into C:/Program Files (x86)/steam/steamapps/common/skyrim - if it is already there then I would rename the skyrim folder to skyrim-backup or something like that. Then install Steam and Skyrim, which will create a new skyrim folder and put the new files in there.

Now for your mods; this depends on what mods you're using. The vast majority of Skyrim mods use the standard master/plugin/archive system present in most Bethesda RPG titles. So open the skyrim/data and skyrim-backup/data folders in separate windows - the new folder will be a lot emptier than the old one. In the old folder, select all (ctrl + A) then unselect (ctrl + click) the following files:

• skyrim.esm
• update.esm
• dawnguard.esm (if present)
• heathfires.esm (if present)
• dragonborn.esm (if present)
• HighResTexturePack01.esp (if present)
• HighResTexturePack02.esp (if present)
• HighResTexturePack01.esp (if present)
• skyrim-<something>.bsa (where <something> is a word, such as skyrim-animations.bsa - there will be a few of these)
• interface folder
• strings folder
• video folder

Now that you have those unselected, copy the rest of the files into your new skyrim/data folder. Start the game using the launcher and click on "Data Files" in there (if that doesn't show, look at this post). Now select all of the files to enable all of the mods. Bear in mind you may have had some of these disabled previously but if your account was lost there's no way of knowing.

You should now be able to play as before, with your mods. Some notes:

The three folders not copied could contain mod specific files (though few mods use these folders). I told you to skip them as overwriting could cause problems with the new game installation. See how the game plays and if any text is incorrect or the UI looks wrong then check to see which files the new installation is missing from those three folders.

If your user account was lost then your save were most likely lost too. If you (or the family friend) have a backup of the old documents folder then you could copy the documents/my games/skyrim/saves folder to the new one.

If you were using a mod manager like Nexus Mod Manager or Mod Organiser they will both need to have the mods redownloaded. NMM will read the plugins but for actual mod management you'll need to download them again, unless you can find the old mod storage location which is usually something like C:/games/nexus mod manager/mods - this will save you from downloading them again.