Browser freezes up

[2hands]

I have a PIIIE 700MHz, 512Mb PC100 SDRAM, 64Mb NVidia Graphics card and 120Gig HDD all running on WIN 98SE...........

All of a sudden with no changes to anything I'm aware of (I do have a 16yr old son!...who swears blind he didn't do anything), has developed a very odd problem.
Whenever entering any text, either search engine or posts, it freezes the browser for anywhere up to a minute before finally chugging along again.
Bringing up the "Close program" box shows browser "not responding".
I use Avant Browser as well as IE and the problem occurs in both
All available updates have been done to both IE and Win 98SE and my system appears to be virus and spyware free.
Any assistance greatly appreciated

[patio]

Have you done all the regular scans for baddies ? ?
Try that first. Then look on the web for keylogger detectors, it's possible you have one on your system.

patio.  

[Raptor]

Use Mozilla Firefox.

Virus scanners
AVG Free
-- Anti virus scanner
Trend Micro Housecall
-- Online anti virus scanner.

Anti spy/malware
Microsoft Antispyware
-- Anti spyware scanner. Windows XP Home and Professional only.
Spybot Search & Destroy
-- Anti spyware scanner
Adaware SE Personal
-- Anti spyware scanner

Firewalls
Use both a hardware and software firewall.
Be advised as dual software firewalls may cause problems

ZoneAlarm Free
-- Free firewall - more user friendly
Sygate Personal
-- Free firewall - more configuration options

Removal tools
The following files are not substitutes for the ones described above.
They are either diagnostic tools or removal tools for malware of a certain kind

HijackThis
-- Manual malware remover. Post the HijackThis log generated only if requested!
McAfee Stinger
-- Virus removal tool. No substitute for a fully functional virus scanner!
CWshredder
-- CoolWebSearch removal tool. Widely known and persistant Hijacker.

[2hands]

Thank you for the quick responses

patio: Ad-Aware SE Personel is up to date and can find nothing  :-/

Antivir Personel Edition Classic up to date and can find nothing  :-/
Will try a keylogger detector and see what happens

Raptor: I have been thinking of using Firefox for a while and this could well be the push I needed. Thanks for the advice.  

[2hands]

All scans clear!
Used Antivir, Ad-AwareSE and Trend Micro Housecall...
Just noted another problem which seems to be related.
I use Memturbo which is now taking up to 30 seconds to load on start up instead of almost instantly like it used to..... also the game Starcraft is now pausing on the menu screen when you start a game whereas before this did not happen.
No other programs appear to be affected
All programs work properly after pause.....very odd
I did run a Hijackthis test.... but being a mechanic not a computer guru really don't understand what it is telling me
I am thinking of purchasing Spycop or the like and trying that

Wish me luck

[2hands]

Well Raptor........ using Mozilla Firefox and low and behold instant browsing  
Still like to know why the problem occurred though
Thanks for the help

[patio]

Dump MemTurbo...memory optimisers are junk and cause nothing but headaches.
If they worked properly and provided decent results you would have already seen them recommended here.

patio.