There is a malware/virus that looks similar to the search function of XP. The times I have seen it, it went full screen and was pretending to do a scan. When it gets done it will tell you that your computer is in need of a particular item or service and prompts for an answer. I did not let it complete and shut down the browser before any damage was done. I have seen the results of the completion and trying to get rid of it was a bear.
The next time it comes up, see what the name of the program is by looking either at the name in the upper left of the program window in the blue bar or look in the Task Bar. Then Google for that program name for results. If it really is the Windows Search Tool, something has altered its processes. Have you run a virus/malware scan?
I'm not sure what is happening, but the search box in XP seems to pop up randomly and often. As in 4-5 times a minute. Sometimes it seems to be because of random mouse clicks, but I'm not sure.
Either way, this has made doing anything quite difficult. Anyone know of a possible solution? Thanks!