I had used Window World for a house I owned in 2009 with great results. I recently sold that house and moved into a new one (early 2016) that needed new windows and went with Window World since I had a nice experience with them previously. Ugh, big mistake. The actual windows themselves are fine, but the service was so horrible it would have been comical if I didn't have to deal with the results and the continual follow up in an attempt to fix my issues.
First off the sales person made a mistake on the order and I ended up with only one privacy frosted window when I actually ordered two privacy frosted windows. I tried to remedy this issue, but really I didn't want them to remove the clear window and install a frosted window because they had caused property damage with other windows and I didn't want to risk more damage. Also the company refused to acknowledge the mistake, they explained to me how I had "changed my mind" or maybe my husband changed the order (I'm not married, I was the only one dealing with the company, and my name was the only name on the documents). I also didn't want to wait another 7 weeks to have a new window manufactured and invite not so great characters into my home for yet another uncomfortable installation.
There were two guys that came to remove/install the windows, one guy was okay but missing most of the day because he was at home improvement stores looking for tiles to replace the ones that were broken when removing my old patio door to install the new one. The other guy was swearing and yelling and just generally making comments about how unhappy he was about doing this work - how uncomfortable and potentially dangerous! When I brought this up to manager he said that he knows the guys on my job and they never use that kind of language, but he's not saying he doesn't believe me. Sure. I'm not even sure they know who they send out on the jobs anyway because my form had whiteout over the installer's name with a name written over it, but that name wasn't the name of either of the guys that were there! As soon as they had left after the installation I knew I would need to call someone to come back because the caulking was done in a rush and had huge gaps that should have been filled. I didn't feel comfortable bringing it up at the time because the one guy seemed so angry and potentially dangerous.
When I called and asked for someone different to be sent out to re-do the caulking (and air my other complaints), they did not seem to think any of my issues were valid, did not provide me with solutions, and they sent the same guy from the installation. Even the second time around the guy still missed spots in the caulking and was in an incredible hurry. It's hard to get anything done when the company just doesn't want to acknowledge any issues. Hopefully I don't have to use the life-time warranty for any reason, I can only imagine they fight I'd have to go through to get warranty service.