Hi Jas jasjas,
Do you receive any error codes?
You may try the following steps and check if it helps:
Method 1:
You may try installing the standalone package of the update and check if it helps:
Microsoft .NET Framework 4 (Standalone Installer)
Method 2:
If the issue persists, you may use the .NET Framework Cleanup Tool to uninstall the installed versions of .NET Framework. Thereafter, try installing them manually.
For further information, refer the article:
Error codes “0x80070643” or “0x643” occur when you install the .NET Framework updates