I have a 0.5m USB-A to USB-B cable and I needed a longer cable I just bought a 2m USB-A extender and it doesn't work with the extender but it works without the extender. It says Device is not recognized, I tried on different computers. Is the extender the culprit?
If you have a cable that works and one that doesnt then clearly the one that does not work is the issue.
Yeah but it powers the Arduino normally, just Windows doesn't recognize it.
Yeah but it powers the Arduino normally, just Windows doesn't recognize it.
In a USB-2 cable there are 4 wires/connections (power, ground, and 2 data wires). And, it's supposed to be good up to 5 meters.
...There's a "rule" of troubleshooting/debugging that you never really know what the problem was 'till it's fixed... If a new/different extension fixes the problem, the cable was the problem. 
For 2 m you should not have any problems at all. Just get a regular 2 m cable. Dump that extender thing. It's pointless for that length when 2 m USB cables are cheap as dirt. Just make sure the cable you get is for data, not a charge-only cable.
Once you need much longer than 2 m is when you'll start running into problems. Just because you're getting some power through them, doesn't mean you will get good data. It's really a pain to go long distances with USB. I needed a 8 m cable and ended up buying a few different cables before I found one that even worked. Some of the ones that did work stopped working after a while. I've been using this one for a while now and it's OK, but every once in a while the keyboard stops being recognized:
I have a powered USB hub on the end and I use it with all my Arduino boards, as well as a mouse and keyboard.
I have a few 2m USB extender cables and I have never had any problem using them. I was using one with a Mega yesterday.
...R
2 Mtr and a 3 Mtr here used to run two CNC GRBL machines.
Both have a ferrite embedded on them and both are what I would term "commercial" quality being quite thick.
Some of these CNC runs are many hours and not a single glitch.
You get what you pay for so do not cheap out on good cables.
We often hear of cheap blue cables and I do have to say the semi translucent blue ones that often come with clones are the only ones that have really failed on me but only two out of about 40 of them.
Micro USB cables I sort out into two bags as I use a lot for POWER ONLY projects and as already mentioned there are two types.