Installed 7.7 on Windows 8.1 with no problem. But...
I had stopped using 7.4 because of its penchant for eating files but when I saw that people were working on it again, I thought I'd give it another shot because I really like the program. But just to be safe I am keeping a copy of each file in jEdit, saved in another place.
I had finished a file, saved the book and started a new file. finished the new one and copied it. Went to jEdit, clicked New file, pasted it in, and bam, jEdit throws up an error notice; not in the new file but the previous one.
The error was <pclass="bot">. Corrected and saved it, then went back to Sigil to make the correction there. But Sigil had deleted everything from and including that error up to </body>, about half the file. At no time did Sigil give me any kind of error notice.
Files created by Sigil end thusly:
</body>
</html>
When it eats part of a file, that changes to:
</body></html>
I sincerely wish all error-checking would be removed from Sigil. It's not that smart, it's not that helpful, and it's somewhere in the error checking that this bug is lurking. I very strongly suspect during save.