I just thought I should let you know that I've found a way to get them working! These old cards are still way better than most (all?) onboard soundcards.
I found an alternative driver pack, which works perfectly on Windows 7 x64, and as such my old Creative Soundblaster Live 5.1 is now resurrected.
If you're in the same situation, check: http://kxproject.lugosoft.com/ and download the drivers. It's easy to install, and then it takes a little bit to set up properly, but then it works flawlessly (well, I haven't noticed any problems yet).
# The E-mu Audio Production Studio (APS) card
# The motherboard models of 10k1 cards (M002, M003 and others)
# PCI256 (CT4890, CT4891 and CT4893) and PCI512 (CT4820 and SB0150) including OEM model (CT4790)
# The original Live! (CT4620) and Live! Value cards (CT4670)
# The Live! X-Gamer, Live! MP3+, Live! Player 1024, Live! Platinum cards (CT4760) and value cards (CT4780)
# The Live! X-Gamer 5.1, Live! MP3+ 5.1, Live! Player 5.1, Live! Platinum 5.1, Live! Digital Entertainment 5.1 cards (SB0060, SB0100, SB0102, SB0220, SB0222, SB0103 and SB0105) and Value 5.1 (SB0101)
# The generic and custom OEM Live cards (CT4830, CT4831, CT4832, CT4850, CT4870, CT4871 and CT4872)
# The Audigy series, including the Audigy MP3+, X-Gamer, Platinum and OEM cards (CT0070, CT0072, SB0090 and SB0092).
# The Audigy 2 series, including Gamer, Platinum, Platinum eX and OEM cards (SB0242, SB0244, SB0320, SB0240, SB0240P, SB0280).
# The Audigy 2 ZS series, including Audigy 2 ZS Gamer, Platinum and OEM cards (SB0350).
The Audigy 2 ZS Platinum Pro is not fully supported yet. There are issues with the line in ADC.
24/96 support for the Audigy 2 and Audigy 2 ZS cards is under development.
# Audigy 2 Value (SB0400), Audigy 2 ZS Notebook (SB0350) and Audigy 4 Pro (SB0380) cards are partially supported.
# The Dell OEM SB Live! (SB020x) is not yet supported since it uses a custom version of the EMU10k1, whose details are unknown. Experimental support may be provided when more information about it becomes available.
# Soundblaster Live! 5.1 cards (SB022x) are supported.
# Soundblaster Live! 24 Bit and Audigy LS are incompatible with kX, since they do not use the 10kX chips.
# Audigy2 ZS Notebook is supported, although some limitations apply.
# E-mu E-DSP based PCI devices are supported (0404, 1212, 1820, ...).
# Extigy is NOT supported and will not be supported.
# X-Fi is NOT supported and will not be supported.