Because I just went through this - I wanted to give my solution even though this is a bit old.
I have several computers on a home router and I have been working on some projects for myself. Well, I wanted to see what it looked like on my mobil devices. But WAMP was set so I could only get on from the development system. So I began looking around and found this article as well as some others. The problem is - none of them worked for me. So I was left to figure this out on my own.
My solution:
First, in the HTTPD.CONF file you need to add one line to the end of the list of what devices are allowed to access your WAMP server. So instead of:
# Require all granted
# onlineoffline tag - don't remove
Order Deny,Allow
Deny from all
Allow from 127.0.0.1
Allow from ::1
Allow from localhost
make it:
# Require all granted
# onlineoffline tag - don't remove
Order Deny,Allow
Deny from all
Allow from 127.0.0.1
Allow from ::1
Allow from localhost
Allow from 192.168.78
The above says that any device that is on your router (the '78' is just an arbitrary number picked for this solution. It should be whatever your router is set up for. So it might be 192.168.1 or 192.168.0 or even 192.168.254 - you have to look it up on your router.) can now access your server.
The above did NOT do anything for me - at first. There is more you need to do. But first - what you do NOT need to do. You do NOT need to change the WAMP setting from Offline to Online. FOR ME - changing that setting doesn't do anything. Unknown why - it just doesn't. So change it if you want - but I don't think it needs to be changed.
So what else DOES need to be changed? You have to go all the way back to the beginning of the httpd.conf file for this next change and it is really simple. You have to add a new line after the
Listen Localhost:80
add
Listen 192.168.78.###:80
Where the "###" is what IP your server is on. So let's say your server is on IP number 234. Then the above command would become
Listen localhost:80
Listen 192.168.78.234:80
Again - the '78' is just an arbitrary number I picked. To get your real IP number you have to open a command window and type in
ipconfig/all
command. Look for what your TCP/IPv4 number is and set it to that number or TCP/IPv6 if that is all you have (although on internal router sets you usually have an IPv4 number).
Note: In case you do not know how to bring up a command window - you click on Start, select the "Run" option, and type "cmd.exe" in to the dialog box without the quotes. On newer systems (since they keep changing everything) it might be the white windows icon or the circle or Bill Gates jumping up and down. Whatever it is - click on it.
Once you have done the above - restart all services and everything should come up just fine.
Finally - why? Why do you have to change the Listen command? It has to do with localhost. 'localhost' is set to 127.0.0.1 and NOT your IP address by default. This can be found in your host file which is usually found in the system32 folder under Windows but probably has been moved by Microsoft to somewhere else. Look it up online for where it is and go look at it. If you see a lot of sex, porn, etc sites in your localhost host file - you need to get rid of them (unless that is your thing). I suggest RogueKiller (at AdLice.com) be used to take a look at your system because it can reset your host file for you.
If your host file is normal though - it should contain just one entry and that entry is to set localhost to 127.0.0.1. That is why using localhost in the httpd.conf file makes it so you only can work on everything and see everything from your server computer.
So if you feel adventurous - change your host file and leave the Listen command alone OR just change the Listen command to listen to port 80 on your server.
NEW (I forgot to put in this part)
You MAY have to change your TCP/IP address. (Mine is already set up so I didn't need to do this.) You will need to look up for your OS how to get to where your TCP/IP address is defined. Under Windows XP this was Control Panel->Network Connections. This has changed in later OSs so you have to look up how to get there. Anyway, once there you will see your Wireless Network Connection or Local Area Connection (Windows). Basically WIFI or Ethernet cable. Select the one that is active and in use. Under Windows you then right-click and select Properties. A dialog should pop-up and you should see a list of checkboxes with what they are to the side. Look for the one that is for TCP/IP. There should be one that says TCP/IP v4. Select it. (If there isn't one - you should proceed with caution.) Click the Properties button and you should get another dialog box. This one shows either "Obtain an IP address automatically" or "Use the following IP address" selected. If it is the first one then you have to change it to the second one. BUT BEFORE YOU DO THAT - bring up a command window and type in the ipcongfig/all command so you have, right there in front of you, what your default gateway is. Then change it from "Obtain..." to "Use...". Where it says "IP address" put in the IP address you want to always use. This is the IP address you put in on the Listen command above. The second line (Subnet mask) usually is 255.255.255.0 meaning only the last number (ie: 0) changes. Then, looking back at the command window put in your default gateway. Last, but not least, when you changed from "Obtain..." to "Use..." the DNS settings may have changed. If the section which deals with DNS settings has changed to "Use..." and it is blank - the answer is simple. Just look at that ipconfig/all output, find the DNS setting(s) there and put them in to the fields provided. Once done click the OK button and then click the second OK button. Once the dialog closes you may have to reboot your system for the changes to take effect. Try it out by going to Google or Stack Overflow. If you can still go places - then no reboot is required. Otherwise, reboot. Remember! If you can't get on the internet afterwards all you do is go back and reset everything to the "Obtain..." option. The most likely reason, after making the changes, that you can no longer get on the internet is because the TCP/IP address you chose to use is already in use by the router. The saying "There can be only one" goes for TCP/IP addresses too. This is why I always pick a high one-hundreds number or a low two-hundreds number. Because most DHCP set ups use numbers less than fifty. So in this way you don't collide with someone else's TCP/IP number.
This is how I fixed my problem.