sean2196 :
I've tried everything.
Method 1: You may try these solutions;
>> Run these commands in Command Prompt (Admin).
a. PressWindows key +X.
b. Click oncommand Prompt (Administrator).
On the open Command Prompt window copy and paste the commands (one by one and on this order) –
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver
pause
c. Wait for the process to complete.
d. Close the Command Prompt.
Now, try to install the .net framework 3.5 again. Check if it helps.
Method 2: Run the System update readiness tool.
a. PressWindows key + X.
b. Clickcommand prompt (Run as administrator).
c. In the Administrator: Command Prompt window, type the following commands. Press theEnter key after each command:
DISM.exe /Online /Cleanup-image /Scanhealth
DISM.exe /Online /Cleanup-image /Restorehealth
d. To close the Administrator: Command prompt window, typeExit, and then press Enter.
e. RunWindows Update again also try to install .Net Framework.
Method 3: Temporarily disable third party security software (anti-viruses, etc). And try again your installation.