Cleaned my keyboard and now the usb ports function but the keys have no response . Is this repairable or do I need to purchase a new keyboard ?

click start control panel administration tools computer management device manager scroll to keyboards you might see a yellow exclamation or question mark or red x you will need to update driver right click to update driver
make sure the usb device is inserted correctly into the usb port (if applicable)
if your computer came with a motherboard disk the drivers could be on it
also if this fails to fix the problemclick start control panel administrive tools computer management device manager scroll down universal serial bus controllers you should see a yellow question mark?
right click to reinstall drivers
if you can see your usb drive but its not working
ports(com&lpt)right click update driver if this fails to fix the problem
check the USB leads that attach to the motherboard usually red white green black make sure they are securely seated and have no dust build up on them dust will cause static and a lot of unforeseen problems for a computer and its parts also
scroll to disk drives if you can see your drive + to expand right click you should see options update driver disable uninstall scan for hardware changes
select properties you should see options in the general tab to troubleshoot policies volumes driver and details under the driver tab you will have the options to check the driver details update driver rollback driver or uninstall
if your computer came with a motherboard disk the drivers could be on it
hope this helps

Was the keyboard working before you cleaned it? Did you removed the keyboard connector, might just be loose connection. Check the connection again and see if it works. Keyboards faults normally starts with one or few keys not responding properly, and if the entire keyboard doesn't seem to respond then it's most likely faulty.

If this doesn't fix then you need to buy yourself a new keyboard.

hope this helps.