I have been using the solution for two to three years.

I have been using Windows Server Failover Clustering as a partner for five years. We are using the latest version of the solution.

I have been using Windows Server Failover Clustering for approximately seven years.

I have been using the solution for seven years.

I have been using this solution for twenty years.

I've been using the solution for about 10 years now. It's been a decade or so. It's been a long time.

I've used it for two years.