Oderowilliams,
Welcome to Seven Forums.
This does not directly answer you question, but I noticed that you say that you have 512 kb ram.
Technically, 512 kb ram is sufficient,however, the performance will be abysmal from my experience. You need a bare minimum of 1 GB to enjoy Win 7.
I also have Win 7 Ultimate and have 4 GB although I also have a netbook with only 2 GB. Both work fine. The netbook is slow, comparatively, but that is mainly due to a slow processor.
Now to your question.
Have you gone to the manufacturer's website to see if they have Win 7 drivers for your computer? Normally, the drivers that come with Win 7 will suffice, although not always ideally. did you perhaps try to install a driver for XP or Vista rather than a driver designed for Win 7?
Go into Device Manager and let us know which, if any, devices have yellow triangles.
WIN | type DEVMGMT.MSC | ENTER key
WIN is the key with the wavy flag.