PC Hang when on Internet

[aviwil]

I have an ASUS A7V with Athlon 1Ghz , 128 MB Memory , ATX Midi case 300 W and 4 yrs old ,Win '98 SE , and 750kbps ADSL line with a cheap router and a cheap NIC .
Since installing the ADSL link sometimes when connected to the Internet the PC hangs . I see that the modem symbol in the task bar shows no data sent/received at the time . What might be the problem ?
Thanks .

 

[SaintTigurius]

Spyware !!!!!!!!!!!!!!!!!!!!

 

[EdfromCocoa]

D/L Adaware and Spybot.

 

[aviwil]

Thanks very much kind people - it was indeed spyware - and Adaware fixed it .