Hello Edward Cyngier,
Do you mean that you cant choose the important update to install? Please share us a screenshot.
Is this computer domain-joined?
In the start search box, type gpedit.msc and press enter.
Navigate to Computer Configuration-> Administrative Templates -> Windows Component -> Windows Update. Make sure the states of all setting are Not Configured.
Navigate to Computer Configuration-> Administrative Templates-> System-> Internet Communication Management-> Internet Communication settings. Make sure the state of Turn off access to all Windows Update features is Not Configured
Please download and install the System update readiness tool for Windows 7.
https://www.microsoft.com/en-hk/download/details.aspx?id=20858
Best regards,
Fangzhou CHEN