Portable Drive Space Indicator

Keeping track of the amount of free space available onto a system is something quite important because if you need, for example, to transfer a large amount of data, you should go for the partition with the biggest unused area to make sure nothing gets left out.
In case you don't feel like opening My Computer to get the needed information every time, you can utilize a dedicated program that displays in the system tray the current status of each drive. This tool goes by the name of Portable Drive Space Indicator and, as you've already guessed, will run as soon as you unpack it, without requiring any installation on the target PC.
The interface is mainly meant for configuring the running settings of the application, so, by visiting each tab in the main window, you will be able to adjust everything to your liking. The first thing you can do is pick the drives for which you want to view tray notification icons.
The program supports all types of connected drives including optical and network ones, while offering you the possibility to change the type of those you select, by accessing the dedicated function that is only one click away.
With Portable Drive Space Indicator you can have the Indicator Bar displayed for all drives, as well as view floppy drive icons (if any are available) with bars. There are several themes available for giving an original look to the drive icons, so you can opt for a Windows XP, Vista or even Mac OSX appearance.
The shortcuts management and drive diagnostics are some extra features at your disposal while the configuration of the program also provides a varied choice insofar as the data update interval is concerned.
All in all, Portable Drive Space Indicator seems a decent tool if you are looking for a simple means of viewing the free space available on your system, but there are some glitches in its functioning, especially on Windows versions more recent than Vista.