installings 'infected' drive as a secondary drive

Hi.

My nephew asked me if I could fix his computer which is extremely infected with a virus (or viruses). I tried everything I can think of without success. My question is: Could I take his infected hard drive and install it as a secondary drive in my computer so that I could then salvage files off of it on a file by file basis? Would this be safe to do for my computer considering it would not be a start-up/primary drive? The files he most needs to salvage are just jpgs.

Thanks in advance for any advice!