Google 404 not found. Can't find fix

I have Windows xp and I cannot go to any google site. It just keeps saying 404 not found. I originally thought I could live without it and use bing, but I'm finding bing is more time consuming and not great for my kids homeschool lessons. To put it blunt I'm a google fan and it's really bothering me. I have searched up and down for a solution. From what I got was that I could use webmaster tools but I'm not sure how to use it. I've tried to learn it but it's beyond me. I know google tools could maybe help, but I can't get to google anyhow. I've tried explorer, firefox, and chrome. I'm coming to believe it's a virus. I didn't have anitvirus on my computer for a couple months and thought norton was still protecting it but it had lapsed and there was no warning that my subscription was ending. I did realize it ended and got another yr. I kinda hoped it would fix the virus but norton wants more money to scan my computer and "fix it".
I have tried malware, trojan and spybot removals but they are the free versions. I just don't have the $ to have someone else fix it. I'm not sure what you guys do here but it has helped me once before to come here. Thanks for any responses. p.s I just tried to connect to google with my pc in safe mode and it did connect. Here's my computer specs:

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows XP Home Edition, Service Pack 3, 32 bit
Processor: Intel(R) Pentium(R) 4 CPU 2.80GHz, x86 Family 15 Model 2 Stepping 9
Processor Count: 1
RAM: 1279 Mb
Graphics Card: RADEON 7000 / RADEON VE Family (Microsoft Corporation), 64 Mb
Hard Drives: C: Total - 38154 MB, Free - 11037 MB;
Motherboard: ASUSTeK Computer INC., P4S8X-X
Antivirus: Norton Internet Security, Updated: Yes, On-Demand Scanner: Enabled