Syncing iPhone 3G

I just bought a new PC, a HP 200-5480 qd. The first time I synced my phone everything went OK. I authorized it and set up as a new phone. I was able to put music onto it, back up contacts, etc. I tried to sync my phone recently, about a week ago, it asks me to restore from back up or set up as new phone. I choose restore from backup and I get an error:

So, I eject the iPhone and dismiss the error. I open iTunes to try to sync again about 3 days ago and it gives the same option to restore from back up or set up as a new phone. I click restore from back up and I get the above error again. So, I close out and try again by clicking set up as a new phone. iTunes backs up files and all that and everything goes fine. I am able to put songs and pictures on my phone, like normal. I try to uninstall iTunes and all Apple products and turn off my antivirus and firewall and then re-install. Open up iTunes and I get the same error.

I've also gotten these errors at some point:

Any help would be greatly appreciated.