|"dell vostro 3550 i7 2nd gen 6bg 750gb"|
XP is a 32-bit OS, you have way too much RAM installed. 4GB is the max, but 3GB is recommended. Your laptop definitely didn't come with XP pre-installed so why did you downgrade? Remove some of the RAM & see if that helps. As for the audio problem, the XP disk can't possibly contain ALL drivers & definitely doesn't have drivers for hardware that wasn't in existence in 2001. All of your problems are due to the OS downgrade.
Try this audio driver: ftp://ftp.dell.com/audio/R315254.exe
BTW, there is no SP4 for XP. If there is one floating around the internet, it's unofficial & not from Microsoft.
message edited by riider