I had a hard time with AirDroid as well.
I am now using SyncMe Wireless with excellent success. There is no software needed on your PC, you just need to share file permissions to your chosen PC Sync Directory/s, and select the Directory/s on your tablet for your Sync jobs. Add multiple sync jobs wth different instructions to multiple directory's. Automate a job uploading new pictures or files to certain directory's on your PC. Add a Sync job to download a PC directory's contents/changes to your tablet. It is very flexible and I found it easy to setup on my Win 7 PC. I hope it will be just as easy on an XP PC.