CRC Error in downloaded files

All files downloaded from zip to exe displays a CRC Error while extracting archives or installing the application files.

ISP – Unwired (Unwired, Australia) modem via NETGEAR Wireless router (was in Sydney, Australia at the time)
Operating System – Vista (yeah! I know one of the worst OS to be working on!!!)
Laptop – HP

Solutions from Google:
Memory test
Fan Speed test
Downloading the files again
Using other unzip applications (installed most of them now 7-Zip, WinRAR, WinZip, aLZIP)
WinRAR recovery software

Did it work?
No, none of the solutions worked

What did work?
Direct connection (Ethernet cable) to the Unwired Modem without the NETGEAR wireless router

I was using the NETGEAR router to enable me to connect to two laptops. Connecting one of the laptop via Ethernet cable to the Unwired modem without the NETGEAR wireless router finally solved the problem, at least temporarily. Still haven’t figured out completely the problem with the NETGEAR wireless router. I had not used this router for sometime, it could be possible that some settings or files had got corrupted.

I cannot say that this is a definite answer to this problem. But, in case you are working on a similar setup, temporary solution would be to connect to the modem directly via Ethernet cable.

Please feel free to provide inputs with this issue.