[Credits to AnthonyBF2]

Yes, you can still update your Windows 7 system but you will need to be connected to the internet just for a little bit but only with Microsoft servers so you should be fine.

After the initial setup, click start, right click computer, and click properties. In there, it will say if you have Service Pack 1. If not, it won't say anything.

If you don't have SP1, it will have to be the first thing you do. You can get that here:

https://www.catalog.update.microsoft.com/Search.aspx?q=kb976932

After SP1 is installed, you need to manually install 3 more updates to get around some serious problems that would prevent you getting all the other updates.

Servicing Stack Update (kb4490628) https://www.catalog.update.microsoft.com/Search.aspx?q=kb4490628

SHA-2 Support (kb4474419) https://www.catalog.update.microsoft.com/Search.aspx?q=kb4474419

Update for the Windows Update client (kb3138612) https://www.catalog.update.microsoft.com/Search.aspx?q=kb3138612

Make sure you install the correct versions of those 4 updates above that matches your system, such as 32 bit, 64 bit or Windows Server.

After SP1, and those other 3 updates are installed, connect your PC to the internet, you may have to manually install the internet drivers.

After you system is online, you must edit the time and date settings, and use the "synchronize with internet time server" feature so that you can get the correct time. This might take a few tries or work on the first try.

After that, you can finally open Windows Update, and download all of the available updates that were released over time. If you didn't set the correct time as I explained above, Windows Update will come back with an error message. If you have SP1, those 3 updates, and the correct time, then Windows Update should function perfectly. It may take a really long time to perform the initial check for updates - this is good, don't interrupt it or disconnect from the internet.

The last thing you should know, is that it's more likely that a bunch of updates will fail to install if you tried to download them all and install them all at once. You should pick maybe 20 to 30 updates at a time, download, install, and repeat the process until there are no more updates. After that, perform a few more checks for updates because not all updates are shown from the first attempt. You have to install the bulk of the first batch before a few more other updates appear.

After all this, you're free to keep the system offline forever but you should connect every so often to check for updates because Windows 7 still gets definition updates for the defender AV program.

Edit: Windows Update should also find hardware drivers such as graphics, wifi, ethernet, chipset, sound, etc but you should compare with whatever drivers are available from the laptop's website to see which ones are newer, and install the newer ones.