Most Nancy Drew games (except for the first two) will install and run on 64-bit Windows 7 using compatibility mode. So it's worth trying to configure them on Windows 10. HerInteractive has tips for installing on Windows 10 here
http://www.herinteractive.com/2015/12/windows-10-game-installation/Treasure in the Royal Tower and Final Scene (two of the early games) can't be installed at the same time, no matter what version of Windows you're using. This also occurred back when the game first came out and isn't a Windows-10-specific issue. You can read about it at the web archive
***here***. HerInteractive made a "patch" but I never used it and don't know if it works on Windows 7 or later.
+_+_+_+_+_+_+_+_+_+
And about old laptops...
"SirDave" used to have a series of articles about playing older games on old laptops over at JA+, but the links are long since gone or changed. He had similar articles in the Adventure Lantern magazine though, and those are still available. There might be some info there on what laptops to look at. However those are for laptops with Windows 95/98, not XP. Look for the articles on "The Best Way To Play Old Classics" in these issues:
http://www.adventurelantern.com/Magazine/AdventureLantern_Sep2006.pdfpage 29
http://www.adventurelantern.com/Magazine/AdventureLantern_Oct2006.pdfpage 24
http://www.adventurelantern.com/Magazine/AdventureLantern_Nov2006.pdfpage 20
http://www.adventurelantern.com/Magazine/AdventureLantern_Feb2007.pdfpage 23
http://www.adventurelantern.com/Magazine/AdventureLantern_Sept2007.pdfpage 12
http://www.adventurelantern.com/Magazine/AdventureLantern_NovDec2007.pdfpage 10
These aren't Nancy Drew games, but they give an idea what to look for in the way of a Windows 98 laptop. It's also interesting to check out the rest of the magazine and see what games were "current" back in 2006-2007.
One problem with older Windows 95/98 laptops is that the screen may not be very good. I'm not talking about resolution -- I'm talking about colors being "off" -- yellowed or dull or with strange tinted patches. This may or may not bother you. As you continue to play with the old laptop, you get used to it. But moving back and forth between an old laptop and a new one you'll see a difference. Most old laptops will have a VGA output and can be plugged into an appropriate monitor, but it sounds like all you have is another laptop.
Screens on laptops that shipped with XP will be much better. However if you get one with widescreen that may cause an issue with full screen games.
It's probably not an issue with the older Nancy Drew games, but other Windows 98 games may require a video card with discrete video memory, and you won't find that on Windows 98 laptops.
Battery life is not good on older laptops either, even if you buy a "fresh" battery. Plan to use the laptop plugged in. The people who use and collect these old laptops usually service the laptops themselves, or have a friend who will do it for them if there is a problem.
If you decide to try an old laptop, you may want to check Craigslist (not just eBay) and see if any are offered in your area. That way you might be able to see it before buying it.