Recently installed fresh copy of Windows XP SP2 onto a new SSD and updated it to SP3. My old hard drive is used for data storage now. I also have an external hard drive. I have 4 gb of ram installed (I know Windows only uses about 3). The boot time of the system has improved very much.
The problem I'm having is that whenever I try to transfer files, the file transfer slows down tremendously. I might be transferring a 60 mb file with the extension .db from my external drive to the internal storage drive and the file transfer will go from saying 5 seconds remaining, to 10 seconds, to 20 and it takes forever. If I cancel the file transfer, sometimes, I am unable to close out the explorer windows, or change folders or right click on the folders. They might show a "not responding" text next to the title. Usually, my start menu and task bar becomes disabled/inaccessible. I can't click on things, right click or use windows key. Sometimes, I have to force quit the explorer.exe, and sometimes it crashes on its own. The start menu disappears, and if I run "explorer.exe" through task manager, it opens up a new explorer window, but I have to reboot to get everything working again.
For my SSD, I use Samsung Magician and have Indexing disabled, prefetcher disabled and power settings set my samsung magician. I updated the Intel controller for the drives, and "Write caching" is enabled in the disk policies. I have also tried toggling the Data Execution Protection for explorer.exe, but that did not work and currently, I have DEP on for everything. Sometimes, this hanging occurs simply browsing through the explorer. I installed a 3rd party file manager "ExplorerXP" but encountered the same problem there. I have also run chkdsk and defrag the interal storage drive. All my services are at their default settings. I used HDTune Pro Trial and the internal drive seemed to match benchmark averages.
Edit: I booted into safe mode and attempt to copy a troublesome file from the external hard drive to the internal hard drive. But the problem remained. I was able to copy the same file from the external hard drive to a small USB flash drive within 5 seconds, and copy it back to the external hard drive in similar time.
Sounds more like a chipset USB problem than anything else, might update those drivers if you have any. Reset DEP to default, disable write caching on ALL External drives and devices (default and recommended), don't buy USB storage connecting devices. USB uses a "translation" process that does not even come close to the advertised speed. Get eSATA if you can.