How do I upgrade IOS on a cisco switch?

Hello friends, I have network configured for my office which has around 20 computers. All the computers are connected to two Cisco switches. Recently I upgraded the operating system on some of the computers and after that the switches started to reboot on its own which is creating problems in my office network. One of my friend suggested that I should get the IOS of the switches upgraded. Therefore want to know How to upgrade IOS on a cisco switch. Any suggestions/solutions about the problem are welcome. Thanks in advance.

You have mentioned that you have upgraded the operating system on some of the computers on the network. If the you have upgraded the operating system to Windows 7 then it might be the reason why the switches are restarting. The default IP version of Windows 7 is IPv6 while the default version of the Windows xp is IPv4. When the computers running on these operating system are connected on the same network, then there would be protocol mismatch. Disable the IPv6 support of Windows 7 and then see if the switches restarts or not. To disable the IPv6 support, open the network connection wizard and go to Lan properties. Open TCP/IP properties and then remove the check mark from the option which says "Enable IPv6". Save and apply the settings.

Upgrading IOS on the Cisco switches and routers is a very simple procedure. You just need a console cable and an Internet connection to upgrade the IOS on the devices. Connect the device on which you want to upgrade the IOS to the computer using console cable. Open the official website of Cisco and go to downloads section. Enter the model no of the switch which you want to upgrade. Once the model number is entered, the website will give you link to download the latest IOS which is available for the model of the switch you are using. Download it and then install it on the switch. Before upgrading the IOS, back up the configuration of the switch if it is configured.

Thank you for replying to the post really fast. I followed your instructions and went of official Cisco site. In the download section when I entered the model number of the Switch, it didnt give me one result but number of results and hence I dont know which of the upgrade for IOS should be downloaded. Therefore I need help in selecting the appropriate update for my switch. The model no of the switch c3560.

There are many variants of the c3560 switch which are available depending on the memory which is available. Check the memory specifications of the switch which you are using and download the IOS upgrade which is available for the variant of the switch. Try and download the IOS upgrade which has IP BASE WITH WEB BASED DEV MGR because it helps in configuring the switch with relatively more ease. Note that you should download the .bin file and not the .tar file as the .tar file is not supported in all the variants of the switch.