Vostro 1014 Missing Base System Device After Win 7 Reload

Hi guys, hope someone can help. I had to reload win 7 (yes I know, it's not supported anymore)  Having checked the device manager, there is no Base system device showing. I cannot carry out a update as Win 7 is not supported anymore. I've looked on the dell website at the drivers but none are available to download for the Base System Device. I have downloaded - Intel PM45 Express Chipset Family, GM45 Express Chipset Family, PM55 Express Chipset Family, Cantiga Chipset, v.9.1.1.1014, A00 , but still no Base System Device? Can anyone help please? I need step by step assistance if possible as I'm not a techy.

Thanks - Julian