Suspect Service/Software

Hi there,
I have a service running that points to an exe file in my windows temp dir,
every time I end the service the exe file disappears and will reappear later,
every time the file appears it has a different file name. e.g. FA31DC.exe
normally after ending the service 3 or 4 times it doesnt start up again for
quite some time unless I reboot the system.

I have Trend Micro installed and have done scans via Symantec and have also
scanned with the windows Mal ware software removal tool, I have looked in the
registry to see whats starting up when windows boots and haven’t found
anything odd in there and have also run 2 different spyware software packages
to see if they picked anything up.

When I look at the properties from the service the only information is the
location of the exe file, and when I get the properties from the exe there
are no details, , I am not experiencing any abnormal issues with the pc, no
popups, no degraded system preformance, I havent been able to see if it is
accessing the network.

I was wondering if anyone had any suggestions as to what this might be
(looks real suss to me) and how I might remove it or find out what is
generating the exe file.
Regards
TIA
Mike