Moved to Malware Discussion > Home User Assistance.
Some more information would help us to help you such as, is this a Consumer or Enterprise product that you are trying to install and what is your operating system, service pack etc. etc. ??
You say there is no IT.exe file on your machine. There well may be but probably hiddden. In Windows Explorer (documents pages or Computer etc.) go to Tools/Folder Options/View and check the "Show Hidden Files & Folder item, click Apply and OK.
Retry your search making sure that the option to show hidden and system files is chosen.
Without knowing your system that operation varies a bit.
At first glance it would appear to be a file that (perhaps - only a suggestion) that someone would insert when they were inspecting your machine using special tools.
Also did you try searching the registry itself? Go to Start/Run and type in regedit
With My Computer (Computer in Vista/Win 7) highlighted first click File/Export and send your registry to your desktop for later restoration (in case you make mistakes) then click Edit/Find and type in it.exe then click Find Next.
By the way from a Google Search I have gathered this much about it.exe.
The process it.exe = Iconic Tray executable & belongs to the software Iconic Tray by dnSoft Research Group.