Bad end-of-line characters in ht.bat
If you downloaded a zipped distribution of TeX4ht, download a new copy of ht.tab directly (don't forget to rename it to ht.bat). Otherwise, just retype the content of the file.

Problems with recompiling the test file
Issue the clean command, before recompiling the file.

Unknown clean command
This command is a script produced by a successful compilation of test.tex.

Browser is unable to find a txt file of test.html
Check the line `\let\PC=Y' in test.tex is uncommented.