Microsoft doesn't give "exploits" to the government. Microsoft doesn't have the in-house expertise to write many of those exploits. It provides information about verified security vulnerabilities (different from exploits) before they're patched, because their patch schedules are elaborate and necessarily create a window of unpatched vulnerability. Microsoft also gives the same information to many commercial vendors, so they can write antivirus and IPS signatures.
NSA does not need Microsoft's help to break into computers.
NSA does not need Microsoft's help to break into computers.