Over my Head-At a loss

Bought 2nd hand. Nothing installed except OS. Installed avg, Ccleaner, Mozilla. Internet slow as hell. I get on, pages load slower than hand turning, site ads just kill all forward motion. Did the Malware, did the TDSKiller. Just to be sure. Did Belcar, DriverMax (screwed there), Overdrive, etc. Got the info....uninstalled all but Belcar. Updated ViaTech adapter....didnt work. Installed new 1g stick(s)...didnt work. Installed an older Netgear Card...didnt work. Checked at VIA to do adapter update...duh. Have even thought i need a bios update......they know nothing of socket A. Thought maybe sp3 is corrupted... Any info is greatly appreciatted. Setting this pute up for hubby, so he quits messin with our (my) business pute. Surfs "questionable" sites. :eek:
Including additional info not gathered by your service.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows XP Professional, Service Pack 3, 32 bit
Processor: AMD Athlon(tm) XP 1800+, x86 Family 6 Model 8 Stepping 1
Processor Count: 1
RAM: 2031 Mb
Graphics Card: S3 Graphics ProSavageDDR (Microsoft Corporation), 16 Mb
Hard Drives: C: Total - 38154 MB, Free - 26380 MB;
Motherboard: , KM266-8235
Antivirus: AVG AntiVirus Free Edition 2013, Updated: Yes, On-Demand Scanner: Enabled


Socket A
Phoenix Tech v6.00 PG
version-----Biosta 42302e3
Model------AWRDACPI
Chipset----ViaProSavage DDR (KM266/KL266)


Thank You---Thank You --- Frustrated Lynne