以前记录的,现发到网上, 共享给需要的人:
vista/win7下面安装VC6的SP5补丁，但是总是报错误需要MDAC 2.5 or higher ，到微软网站上下了一个MDAC2.8，但是又安装不上去。在国外一个网站上终于找到了一个大牛给出的解决方法。
用记事本打开SP5补丁程序所在目录下的sp598ent.stf 文件
找到下面的行：
13 Group 28 36 38 29 30 32 26 27 14 25 16 17 20 18 19 15 39 21 22 24 23 43
将其替换为：
13 Group 28 38 29 30 32 26 27 14 25 16 17 20 18 19 15 39 21 22 24 23 43
找到下面的行：
36 Depend "27 ? : 37"
37 IsWin95 CustomAction "sp598ent.dll,CheckForMDAC"
将36，37后面的内容都删除掉, (crunch: 是将36, 37行的内容删除掉, 不是将后面的内容删除掉)
保存，退出
再运行setupsp5.exe，嘿嘿，没有再报错误了！！
再次感谢那位叫guideX的大牛，他原创的方法~~
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Though this isn't supported and you get the normal warnings about maybe not working on Windows 7, but i now have it installed and compiling.
Found a solution to this that actually works well. Essentially you have to hand edit the STF file for VS6 Service Pack 5 to skip the MDAC check.
Install VS6. Do a custom install and deselect Visual Analyzer, along with anything else you don't need. I ended up installing InterDev and VC++ with some misc. tools.
Extract Service Pack 5 files to a folder.
Modify SP598ENT.STF to remove 36 (the MDAC check) from the list in step 13
13 Group 28 36 38 29 30 32 26 27 14 25 16 17 20 18 19 15 39 21 22 24 23 43
and save the file. For completeness, you can remove step 36 (and 37) entirely, but it isn't necessary. Those lines are as follows (and it's safe to remove them or ignore them, as long as 36 is removed from step 13):
36 Depend "27 ? : 37" 37 IsWin95 CustomAction "sp598ent.dll,CheckForMDAC"
Run SP5SETUP.EXE and let Service Pack 5 finish installing.
Install Processor Pack normally.