I'm not familiar with that product under Windows, although I have used it a long time ago on an Apple Mac.
Some programs will work under Windows XP in compatibility mode and others stubbornly refuse.
I'd imagine that you only have two real choices:
1. Create a partition on your XP computer and install Windows 98 on it, assuming you have partitoning software, the knowledge and experience to use it effectively, and all the relevant device drivers for an older version of Windows.
2. You migrate to a newer web authoring tool that will run on your XP box without misbehaving.
Frankly, I'd far rather try to find a more suitable and up to date program than fiddle about with disk partitions. Sourcing drivers could well be an issue too, since many hardware items are starting to feature Windows 2000 and XP only support.
Adjusting your partitions could bring your entire system to its knees unless you know what you're doing, and for the sake of an outdated program I think the risks far outweigh any potential benefits.
Time to upgrade your web authoring program I think, to a different product.