Can you see if you can download AdwCleaner and run that.
This is a safe program to download just to see if you can download anything else.
https://toolslib.net/downloads/viewdownload/1-adwcleaner/When the scan has completed it may list programs in the lower pane that it considers adware - just uncheck the boxes of any you want to keep.
If it reports it hasn't found anything then click on the Uninstall button, otherwise click on Report log which will open in Notepad to show what it has found and will remove when you close the report and click on Cleaning.
One thing that will stop downloads is Windows Firewall which is active in normal mode if using an antivirus program that doesn't have its own firewall and will be activated in Safe Mode where an active 3rd party antivirus program will be isolated.
BTW - Which version of Windows are you using as running a command prompt with admin privileges varies with version.
If you can fathom how to run a command prompt in that mode then enter chkdsk /f
In Win 7 you go Start - type cmd then right click on cmd and select Run as administrator - accept the UAC and enter that command.
You will be prompted to type and enter y for it to execute the next time you reboot.
Then enter this command to effect an immediate reboot - shutdown /r /t 00
The output will stay on the screen long enough to see if it has found any problems with the files, but also look near the bottom of the report to see if it reports any KBs in bad sectors.
If you miss it then go Start - type eventvwr and press enter.
When Event Viewer has read the data expand Windows Logs - click on the name Applications - Action - Find then type chkdsk or wininit into the Find box and press enter.
Cancel the Find box then read the report in the scrollable window.