I have been familiar with this tool for about five months. 

I have been working with Trend Micro Deep Discovery for six years. 

I have been working with the solution for three years.

I have been using Trend Micro Deep Discovery for a year.

I've used the solution for five years. 

I have been working with Trend Micro Deep Discovery for about one year.

I've worked with Trend Micro solutions for many years on various projects, but I've only used Deep Discovery at this company for three or four years. 

We have been using Trend Micro Deep Discovery for ten months.

We have been using Deep Discovery for a couple of years. 

I have been using Trend Micro Endpoint Encryption for one year.

I have been using Trend Micro Deep Discovery for four to five months.

2 years

I've been using the solution for more than one and a half years.

I have been using this solution for approximately five years.

I have been working with this solution for six months.

I've been handling the solution for quite a long time. It's been many years. I've had a lot of time to work with it. However, I can't say for exactly how long it's been as it's been a while. 

I have been working with Trend Micro Deep Discovery Inspector for two years.