BUT anything reading or writing to the HDD - loading an application or accessing the IE cache, for example - is taking forever.
Very slow hard drive access can occur if the IDE controller channel(s) revert(s) to PIO mode from DMA - check for each controller in Device Manager. It's a "feature" of windows that it can fail back to PIO, but not return to a higher mode.
Sometimes you have to edit registry settings to force it back.
SD