Richard More information is needed to try to give you a definitive answer. With the information given, your description of the problem could be related to the power supply [not enough power (what is its rating?), overheating (is the fan operating OK?), defective (possible but not probable)] or to high CPU and/or motherboard temperature (automatic protection activating - can you monitor the temperature?). Please supply more information which may be helpful in allowing members to direct you in diagnostics and repair: Model Motherboard and/or Computer Identification Amount of RAM Type/Rating of CPU Rating of Power Supply Operating Temperatures (if you can monitor them) Operating System "keeps clicking" = a single click or multiple clicking before rebooting ?? Games being played? Frequency of problem such as - Every time starting IE? Sometimes while using IE? When starting the games? While using the games? Anti Virus being used and last time a scan was done and results (suggest you do one now) May be needed later in the diagnostics though you could supply it now: Model video card or on-board video Model and capacity of hard drive Model or on-board audio Method of connection to the Internet (dial up, DSL, Cable Modem) Hope this helps or that some other member can help. Tom Mayer Hi everyone, this is my first posting to the list so please forgive me if the information I am about to supply is a little scant. I have just had a new PC built for my 11 year old son. The PC came in kit form but the shop built it for me free of charge. I have just tried using it for the first time and it keeps clicking and then rebooting. THis has happend while in internet explorer and while trying to play two games which we have just loaded loaded. Any pointers to what the problem might be would be greatly appreciated and may put a smile back on my son's face. TIA Richard. PCBUILD maintains hundreds of useful files for download visit our download web page at: http://freepctech.com/downloads.shtml