My system is a vanilla desktop circa 2007: Asus PB5 MB, Intel Core 2 Duo, Vista. It worked fine until a Windows update in October; then got "boot mgr missing" errors. I addressed that with helpful advice including a partial (aborted) reinstall. Vista wouldn't let me reinstate user files so I used a Linux boot disk to copy user files from windows.old. Things are almost back to normal except some programs do not appear in menus but can still run (e.g. MS Office). More importantly, neither Firefox nor IE will access the internet. I'm using a 2wire router from my ISP (Bell Canada) with the desktop wired and a wireless laptop. Networking works fine; I can access laptop files from the desktop and vice versa. I can also access the internet from the desktop using the browser on the Linux boot disk, but no internet with Vista, even with Vista firewall turned off (and I get Windows Defender error messages on reboot).
I"m trying to avoid a complete reinstall of all programs. Any advice would be much appreciated.