Stan,
I think
PCV-RS220 PC Desktop is correct and
not 'pc-rs20'?
I can't fathom why SONY would say 2 drives can't be happy together because clearly ~ as shown in the SONY photos ~ physical SPACE, IDE CONNECTIONS and POWER connections are provided for 2 drives!
I have included a SONY link for Hard Drive replacement below for you... and I see yours is a older
"IDE" type hard drive! Please know
IDE HARD DRIVES (CD Drives included) have
JUMPERS that MUST be set correctly!
Your MAIN drive is the "MASTER" and your SECOND drive is the "SLAVE"...
IF BOTH are jumped to "MASTER" I can fully understand
WHY your system and software is confused and I'm SURPRISED that your system would allow you to fully BOOT at all! It's
SLOW because your system is not SURE WHICH DRIVE to go to for the information it needs!
STRONG ADVISE: Just so your SOFTWARE and DRIVERS don't get all jumbled-up and shoved onto the wrong drive, KEEP YOUR COMPUTING TO A MINIMUM until you get your MASTER/SLAVE setting right!
Once your JUMPERS are correct your system will be quite happy and peppy again.
Now
please don't be offended with the title... just GLEAN the info from the PHOTOS to see what I describe.
Also note a "CSEL" jumper? If all else fails read up more on that choice!
Anthony
How to Set Jumpers for Your Computers IDE Drive dummies
https://docs.sony.com/release//T99860136_Rev_C_NO_PHONE.pdf