Recoving 7 Zip Archive - Cannot open file 'xampp.7z' as archive

Cannot open file 'xampp.7z' as archive error.

Hey all, i recently created a backup of all my websites, databases and
many projects, using a backup tool: cobian backup 9.
This created three files for the folder i was backing up (my xampp
directroy)
These were three 7-zip files split into 700mb, 001, 002, and 003.

I copyed these to an external HDD, re-formatted my Main HDD in my
machine, re-insatlled windows and copyed them back over.

I managed to extract these split up files from 001, which should give
me the directory i backed up.. but it didnt it game me another 7-zip
archive, this time an overall of the folder.. so it must have compressed
a compressed file.. THing is i cant read/extract it!

Now i cant open this archive with anything.. and its really important i
get this data back..

I have tryed WinRar, 7-Zip, The 'Tools > Decompresser' in Cobian..

And im really starting to freak out, because i CANNOT lose this data..

What can i do to get my data back?

I really feel for you. Now you know the reason for *testing* a backup first.
You can try to contact the guy who wrote Cobian backup, although I don't
think he's supporting it any more. The alternative - if no one else here has
a suggestion for you - is to contact a professional data recovery company. I
use Drive Savers (www.drivesavers.com). This will not be cheap.

Next time try a different backup program. I like Acronis True Image because
it images your system and does incremental backups.

You could pray a lot... OH, just noticed your moniker.

Oh no, so no-one has used a 7z recovery programme that works?
Most of the things i search, just seem to be a bunch of
rubbish/spyware...

well im not going to lose hope yet, keep trying i suppose..

I used to fool around with these two file-splitting programs:
HJSplit / MegaSplit

These programs split / join files. As a last resort, you might make copies
of your 001, 002 etc. files and try to "join" them into one large 7z
archvie. Then try to extract contents. Good luck.

[Erasmus]

I know some zip archives when you split them like that (assuming you created one archive, and automatically split it into parts, rather than just creating 3 archives) only store the header information in the first archive.

So you can't just extract them separately, you need to tell the extractor it's split into 3 parts and it should process it is as one archive. You tried this?