I have a Sony Viao and a Gateway Computer that both date back to about 1998-1999. The Sony Viao works perfectly, it has served its purpose and has not let me down one single time. The Gateway on the other hand has malfunctioned and a virus has killed the harddrive. The Gateway is a little more powerful than the Sony, so I wanted to replace the strapped harddrive from the Gateway with the exsisting good harddrive from the Sony. Would this task be possible? If so what complications would I run into and how would I solve them?

I would say if it aint broken dont fix it :P The change over would depend on the makes of HD they would be using. Different brands tend to use different components (b---tards hehe) so if you REALLY wanted to do this I would just check the size etc of the HD's first. Id say go onto ebay and try your luck at buying another HD for the Gateway

Should work. Just set the jumpers correctly. Problem may be lockups due to different hardware in the gateway. You can overcome that by first setting the video to standard VGA by changing the display adapter. Then remove all devices in device manager. Start with NIC, modem, sound then monitor, CDrom, harddrive, ports, finally remove the system devices that have a specific chipset name attached to them, like SIS, INTEL, at some point in this you will lose your mouse. When that happens use keyboard windows key to shutdown. You want to shutdown properly to save the changes in hardware you made. Then you can remove and insatall the harddrive and should boot and find new hardware.