'Windows Uptime' Logging Desktop Application Needed

We often test laptop batteries to see how long they will last. The best way for doing this is to play a music CD with visualisations on in Windows Media player. We have a freeware application called 'uptime' which shows how long the system has been powered on for. This shows you on the screen the number of hours and mins. If I see the laptop switch off because it runs out of power, I can switch it back on immediately, and look at the time on the 'uptime' application. The problem is, if I was not in the room when the laptop battery dies, I wont know exactly when it powered off, because the uptime application doesnt have a log. (Also sometimes the battery fails without warning so the laptop would need to be switched on again) So I need a very simple application which shows the user how long the computer has been switched on for, but also logs this data at regular intervals, in case it switches off. I would like it to save to a textfile on the root of the drive it is run from, e.g. F:\ if it is run from a USB stick. I would like it to save at every 1 minute. The logfile would show: 1:00 2:00 3:00 4:00 5:00 6:00 which is what you would see if you opened the text file after 6 minutes. If the battery dies at 24 minutes 30 seconds (and the laptop goes into standby), then I left the laptop for 1 hour 5 mins whilst it is off and then wake it up, it would show: ... 20:00 21:00 22:00 23:00 24:00 1:29:00 so I could still easily work out that it died at 24 minutes because there were no 1 minute intervals between 24:00 and 1:29:00 The application must run in Windows 2000/XP/Vista/7 and show the user that it is running, perhaps by showing current uptime on the screen. Ideally it should be 'always on top' of any other applications. It should be standalone and not require installation. - You MUST be a good communicator (have a good understanding of English and use MSN Messenger or Skype, where you are online at some point during 10.00-17.00 GMT - The project must be completed within 5 days of starting work.