This problem cracks me up. :haha: The issue... I can only upload FTP files that are 1KB or less. The cause... I think... I'm pretty sure this is because of a worm I removed from my computer (sqldbmanager.exe, worm.sdbot.sv), because I didn't notice this symptom until after I treated this. I 'repaired' all the damage done by this worm according to the virus encyclopedias I've found by reverting registry/system settings and deleting/fixing appropriate files. I noticed that this worm utilizes FTP to compromise and distribute information on host and client computers. So maybe this is tied together somehow. The details... This happens with multiple FTP servers and only on this computer. I can connect, change permissions via FTP, create folders and upload files smaller than 1KB. I can download the largest of files with no issues... BIN and ASCII modes work properly and while I usually use Passive mode, I've tried Port mode with no success. I tried directly through the modem as well as through the router without any luck. However, it works perfectly on my laptop using the same software and similar Windows setup. Here's a snippet from my SmartFTP log. System: Windows XP SP2 + latest updates FTP clients: SmartFTP, LeechFTP, FTP.exe (XP cmd client), IE integrated FTP function Firewalls and other network-altering utilities uninstalled. Additional stuff... (Updating this as the thread progresses) Repaired my Winsock via the netsh winsock reset command. Repaired my Winsock via LSP & Winsock Repair programs sfc /scannow performed and passed PASSIVE and Direct PORT modes - no difference BIN & ASCII files using BIN & ASCII modes with different files - no difference No log entries in eventvwr.msc Reinstalled XP Networking Components (Add/Remove Components) Replaced C:\Windows\System32\wininet.dll with an older copy from SP2. It's a weird problem and I'm stumped... I'll format if there's no answers - no big deal - but I like to find solutions. I'm hoping someone here understands more about Windows and FTPing than I do and might be able to come up with some possible reasons for this.