Blank ipad screen

Hi mannan99,

This link has some steps that could help you with your restore error: Get help with iOS update and restore errors - Apple Support.

This link provides additional information that may help as well: If you see an error when you update or restore your iPhone, iPad, or iPod - Apple Support.

Error #4 is most commonly associated with your computers security software interfering with the restore process. Information and guidance can be found here; follow the link to Error #4:

iOS update and restore errors - Apple Support

To resolve the issue, you will most likely need to [temporarily] disable the security/anti-virus software installed on your PC.