No worries. Sorry if I was a bit terse.
After looking for the specs for the 746c...
The computer uses an Intel 82845GE (845GE) northbridge. The Pavilion 746c doesn't include a discrete graphics card, but makes use of the graphics provided by the 845GE. This graphics adapter is referred to as Intel Extreme Graphics.
However, Windows XP was the last version of Windows with official support for Intel Extreme Graphics. Windows Vista included built in support for the graphics adapter, but Intel didn't provide a separate driver, and this driver was not included in Windows 7. Also of note is that Vista could not run Aero (the fancy UI with transparency) on the fairly underpowered graphics hardware, which is probably why support was dropped.
Now, when I search, I see people saying two things:
1) you can manually install the old Windows XP driver under Windows 7 (using device manager to load from the correct .inf file). This will at least give some acceleration to support higher resolutions and decent computer use, but you will not get stellar performance.
2) if you can find the Vista driver extracted by some helpful problem solver, you can manually install that. (Similar to situation 1)
...Force installing drivers may require a little extra effort if Windows rejects an unsigned driver, and the OS could just fail to boot with the shoehorned driver.
Your other option would be to buy a newer graphics card to use in a PCI (not PCI Express) slot or, preferably, in the AGP slot.
I would personally try to get the Windows XP driver from Intel's site (download a zip if possible, or just extract the contents from the exe but DON'T let Intel's installer try to run).