Windows updates issues.

I recently replaced the hard drive on my acer 5720 with a wd 320 gb scorpio blue unit. I cloned the information from my old drive and all appeared ok, at first. I have found since that i can't get windows updates, defender updates and vista mail won't work - i have been using mozilla thunderbird to get me by.

All the symptoms are as this thread

Vista 64-bit Won't Update after Hard Drive Replacement - Microsoft Answers

I have the 32 bit vista home premium os with sp1. If you follow the thread above it appears as though i need to download IRRT drivers, but every one i try doesn't seem to work. One even states that my system doesn't meet minimum requirements. Is my system just too old to work with the hard drive?

Any ideas on how to sort the updates issue welcome, would it be possible to use the acer recovery facility to overwrite windows without erasing all my data, if so how could it be done and would it help.

Hoping to hear from someone, thanks, Andy