I just installed a dimmer switch on a light in my gameroom. After installing the switch and testing it to make sure that it is working properly, I noticed that a couple other light switches on the same circuit in a bedroom next to the gameroom are not working. I don't know what has happened. When I installed the dimmer switch I did flip the breaker off so I could remove the existing light switch and install my new one. After I was finished I flipped the breaker back on tested the light with the new dimmer controller and I thought that everything was working fine, until about 10 minutes later when I went into my bedroom and turned the light switch on and nothing happened, and my closet light is on the same switch and it is not working either, but the gameroom is working just fine. Please help.

Most likely wire(s) got disconnect when installing dimmer.
Turn off Breaker, remove switches with wires attached and check the hots are physically connected together.

Ok, I will try that.

Well I looked for loose wires and could not find any that are loose. I do not know what to do. The dimmer switch and light are working just fine. My bedroom, and closet just are not working and I haven't any ideas why not.

Run your finger down both rows of breakers, with slight pressure, not enough pressure to turn the breaker off, enough to throw a tripped breaker?

Well with no luck, I have tried these tips above and nothing has worked. I will be calling an electrician to come out to the house and take a look at it. Hopefully something very simple that I am just not seeing. I appreciate everyone's advice. Thank you guys.

I would maybe use an Extension cord plugged into a know good receptacle to use as a reference to determine if you lost a Hot OR a Neutral, Or a Hot And Neutral. If you lost both, it is likely fed or protected from a Ground or ARC Fault Breaker.

What do you mean? How would I use an extension cord in this situation? I did get my multimeter and check outlets in the room with no light service and they register 120v. I do think that it might be a loose wire, I just don't know where else to look for a loose wire.

Well I figured it out with the help of a local Electrician. I broke the circuit, I did not know that the power coming in was going on to the next switch, and I also had a couple of wires backwards, which I am lucky it didn't do anything bad. But it is fixed now, and I really appreciate all the help that was given here. Thank you.

What do you mean? How would I use an extension cord in this situation? I did get my multimeter and check outlets in the room with no light service and they register 120v. I do think that it might be a loose wire, I just don't know where else to look for a loose wire.

An Extension cord has a know good hot and a known good neutral. If you plug a lead from tester in extension cord Neutral and other lead into recepticles hot, and you have power, the Neutral is open.
Good you got it going.