I used Trend with XP, a real nightmare, intrusive and caused all manner of problems.

Since going with Windows 8.1 about 2 years ago I have used Windows Defender without a single problem, in the past I have used Norton AV, Trend, Micro and Bit Defender, all had their downside.

Bit Defender automatically renewed my subscription using the credit card details supplied 12 months previously I must have missed ticking/unticking the box for auto renew, try talking to that lot by email and getting any sense out of them, could not cancel the auto renew status, so cancelled the credit card concerned, that was 3 years ago, I still get emails from them to this day, trying to entice me to return, ha, fat chance.

Windows Defender does exactly what its meant to do without any compatibility issues.