Itunes to Iphone problem - Unknown Error (-50)

I'm having a problem syncing songs from Itunes to my Iphone. I manually manage my music in Itunes and after I hit 'sync' or 'allow', it starts the transfer (i.e. 1 out of 758 songs) but then stops after the first or second song. It gives the message "Itunes could not copy 'song' to the Iphone because an unknown error occurred (-50)". I transferred a bunch of music from a friends pc a couple months ago and began experiencing this problem after that.

I have the Iphone 3G, Windows 7, Itunes 9.

Thanks in advance!!

I am also having great trouble with my iPhone 3Gs and Windows 7 Professional 64-bit.

About 99% of the time I get an error message.
"iTunes could not connect to this iPhone because an unknown error occurred (0xE8000065)."

Sometimes the number in parenthesis is different.

Strangely, on rare occasions I am able to sync and load music. The two times I have tried to update the iPhone software the process stops before completion. I have a paperweight until I make an appointment with the Apple Store, drive there, get them to do the update. Then I have to manually put in all my contacts and download apps over my wireless connection. Currently, I have no music on my iPhone as my computer will not connect to the iPhone.

I have iTunes version 9.2.1.4.

My system:
motherboard: Asus P7P55D EVO
CPU: i7-860
RAM: G.Skill Trident 4 x 2 GB DDR3 2000
Graphics: 2 x Ati 4890
PSU: Rosewill 1000w
OS: Windows 7 Professional 64-bit

Hello, I have a simillar but wors problem.

I am using window 7 pro. with MS office 10 and other non Microsoft programs. On Monday while I was updating my iPhone OS to correct a problem with day light saving time, using ITunes, ITunes gave me an error message stating that it lost connection with my iPhone. I rebooted the Laptop and too many problems started to pop up since then. For starters, my iPhone was wiped out, where the only way to restore it was by going to the Apple store. Now, ITunes gives me Error 50?! The Apple Store tech avers that ITunes has nothing to do with the problem.

Since then, the majority of my programs are not working those that run require my permission to execute including Windows components such as control panel, security, uninstall, program install, etc.

Excel and MS Word are working, but Outlook, Outlook safe mode, OneNote, ITunes, Skype, Adobe, windows troubleshoot, McAfee, Chrome, etc. are not working. They all missing important files or give me an error message.

In contrast, I created a new user account without Administrative right. I can run all programs without any problems using this account, except for having to reconfigure everything all over again and having to provide an administrator's permission virtually after every click.

I ran desk defragment and McAfee scans from the new user's account and both ran flawlessly and reported that my system is clean with no virus or bad sectors. I have 180 GB of free space. Any ideas?

Thanks,