How to repair corrupted pdf files after HD crash recovery ?

[Biko001]

After recovering files from my crashed hard-drive all PDF files appear corrupted. Acrobat reader will not open them anymore, nor any other "pdf reader" that I have tried. The error leads back to missing file headers. I don't know how to restore this (I need to repair >5000 personal archive files, so a batch repair would be very helpful).

I tried searching other forum's but could not yet extract an answer that I could use. I might have overlooked so directing me towards an already given solution is also helpful.

THX ...

[moved from non-technical Lounge to Adobe Acrobat Reader forum by moderator]

[Bernd Alheit]

What can you see at the first lines when you open one file in notepad ?

[Biko001]

Opening in notepad only gives me a huge amount of chinese characters.

[~graffiti]

Definitely not code from a pdf file. Either these were not pdf files or they are horribly corrupted beyond repair...

[Abambo]

PDF Headers start with a kind of "%PDF-1.4" (1.4 is the file PDF version).

I know some signatures of different file formats. This does not look for me as one that I saw during my career. I never saw a document with that much Chinese characters. Couldn't it be a real Chinese text file?