Some Windows 98 CD Keys you can try are:
R3TQR-PQTKG-HBVQ9-YBFH3-CGCRT worked with German full, English full (OEM), UK Edition, Compaq English, Spanish Full, Dutch, Compaq and IBM Recovery CDs, and U.S. Second Edition (SE) OEM, Dell SE laptop.
Q2YHH-GYWV2-MDXCD-H9P2X-HYVMM worked with several versions including SE (Second Edition), UK Edition, and US OEM.
R34DV-VB6WM-XMHHV-WM4Q2-WBB3Y is supposed to work with all version of first edition Windows 98 (4.10.98), UK Edition.
T7J8Q-MH7RP-9H9J2-2HVFG-C3X2M worked with four U.S. retail versions (4.10.1998) as well as second edition version.
JJK9P-G8JYJ-X24RC-XTFJ4-K9W4W worked with English retail version (CA), UK Edition.
MMHK7-QPHQG-KMTP9-7GTJY-JQ6XM worked with English Retail Second Edition v4.10.2222A. Also, HP 4440 recovery disk, UK Edition.
XB88B-9B96V-CRJPG-64882-GQBDD Full verison, not upgrade, also Second Edition, UK Edition
DJK2X-6XFJB-Q9J7J-WGC7P-WMHYG Compaq, HP, IBM, etc., UK Edition
HGBRM-RBK3V-M9FXV-YCXDK-V38J4 Apr 98 Beta
BQRYF-BQ4BF-Q4VFX-D9PRC-YTCV7 French Update CD
MD97J-QC7R7-TQJGD-3V2WM-W7PVM came English Developer's Connection Version. Seems to work with same CD's as T7J8Q... above.
HBM43-PD86Y-9R8HM-4GM8H-TVG3Q UK Edition
BHB6V-JYFJ8-V9C47-QDB6B-JCTXK UK Version
Q988C-P7VK2-K2K7R-QX9W9-7CDW3 UK Edition