Alex,

Why don't you uninstall both entries & download just TweakUI from here:
http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx .
You can also download individual applications without downloading the entire
PowerToys.
ps-Be sure to uninstall both entries before installing the new TweakUI or
PowerToys. Read the 'Important' notes on the same site above before
installing.

Drew

EACH powertoy gets its own uninstall entry.  For example, I installed the
following and EACH has it own entry listed in Add/Remove Programs:

   Calculator Powertoy for Windows XP
   CmdHere Powertoy for Windows XP
   Image Resizer Powertoy for Windows XP
   Virtual Desktop Powertoy for Windows XP

However, it is possible that you installed some aggregate install package
that included all of them.  I got mine by going to
http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx and
clicking on each one on the right one at a time.  Since Microsoft says, "If
you installed PowerToys prior to April 23, 2002, you must uninstall your old
PowerToys before installing the versions available here", you should
uninstall them all and reinstall the ones that you want.

Of course, an entry, as you descibed it, saying only "Powertoys" may have
nothing to do with the Powertoys for Windows XP and be some 3rd party
software.  The person in charge of installing software on that computer
should know what is the tersely named "Powertoys" item.  The ones that I
installed all say "<product> Powertoy for Windows XP".