If it's not a valid WIN32 application, no-one can install the program, not even Microsoft. A WIN32 program is a program written for the Windows 32-bit platform, which is all but the pre-Windows 95, and Windows XP 64 and higher.
The administrator in Windows XP Home is found by starting in Safe Mode and selecting Administrator from the list given (or by typing in Administrator). When the Administrator logs in, go to the Control Panel, and select User Accounts. In the box that appears, select an account (such as yours) and follow the links to make it an Administrator account. You should now be sorted.