Can't run safe mode, arrows will not sellect

and no matter what I download will not open, comes with error message *.* infected and will not run, AVG virus will not run, add and remove software will not open, msconfig will notopen error message file has virus m/s explorer will not open only firefox will open, keep getting message to buy AV Security Suite antispyware and porn site keeps opening in windows explorer and will not close only can minimize need HELP. I can't complete any parts of read and do list before posting. I am running window XP Pro on computer. Every time I start to summit add comes up to purchase antispyware

 

Thanks for reply CHASLANG, I downloaded all files you suggested and installed to cd/dvd and tiried to reboot system, still would not let me even open cd with programs, said that each file/program was infected by virus and would not open. I have AVG 9.0 free antivirus and Spybot search and destroy, when I try to run them get error message AVG---the fileavgscanx.exe is infected. Do you want to run your antivirus now and if you say yes then it tries to sell you AV Security Suite from London England if you say no then if just goes away. The same with spybot, the file spybotsd.exe is infected. Do you want to run your antivirus software, if you say yes it tries to sell you AV Security Suite.I can't open any programs except Firefox, M?\/S explorer takes to sell AV Security Suite.I have tried all I know except throwing out second story winndow!!!

 

Thanks Chaslang for help, made me remember I'm wireless mouse and keyboard. I installed wired mouse and keyboard to boot in SAFE mode, then ran cd's and found problem, I restored to earlier date and closed restore to wipe all off. Thanks for help

 

I understood, but could not boot from cd at that time,but am using your malware tutorial to clean entire system. Thanks