You can find PPT repair tools on your own so all those spams will vanish.
The in use can be easily fixed. Reboot. Put it on some FAT32 memory stick or push it up to Google Docs.
There was some user that didn't reveal for many posts the file was fine but not on their XP machine. That was easy to fix too. Use the other PC.
Note; Moderator edited title.
How do I repair a PPT file that has the error message: The file may be corrupt, in use, or of a type not recognized by PowerPoint.?