[mothered]

As with any OS, It's only as secure as how the end-user configures It.

I can secure Windows natively by simply defining a few GPOs, MMC snap-Ins, Increase the cipher strength encryption algorithm on BitLocker and/or EFS, deny "write" access to the OS/System Drive (and other partitions where applicable), Implement Software Restriction Policies to deny file "types" and the list goes on.

Simply stated, the Windows platform can be secured natively to almost bullet-proof It from any Intrusions.