Under See Also in help(parse_Rd, package="tools") it says: Rd2HTML for the converters that use the output of parseRd. Should be "parse_Rd" not "parseRd".
sessionInfo()
R version 2.10.0 Patched (2009-10-26 r50212) i386-pc-mingw32 locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base loaded via a namespace (and not attached): [1] tools_2.10.0 /H