insufficient memory, virus?

hi ppl, it's since a couple of days that i'm having a serious problem with my windows xp
each time i right-click on any file (not dir or else, just on files) i get an error message saying

Insufficient memory!

then i can only click on OK or kill the process, but either way it closes the explorer shell

i've tried everything scanning with nav,adaware,spybot s&d, pest patrol, cwshredder, panda online scan ecc.
the funny thing is that yesterday night i turned on the pc and the problem was gone, then it returned afgter reboot , so i thought about a trojan and installed sygate, but nothing new... hijackthis logs report nothing strange
i haven't found anywhere on the net someone with my problem

my specs are
amd athlon 2000+
512mb ddr
from 768 to 1536mb paging size
i don't know what else i could do or tell you... i need your help!

 

Just for giggles try setting both min and max pagefile size to 768MB and see what happens.

 

Hello,

Is typical for Windows to launch such error messages when disk fragmentation is too "high"; Of course you need to defragment your HDrive or at least XP partition. I suggest you to try this with VoptXP which is far better and
much faster than that poor XP defrag proggy.

please let me know if this helped

good luck,

Stefan

 

since i have had problems with searchx i checked this thread http://forums.spywareinfo.com/index.php?showtopic=13180&hl=searchx
followed the instructions and now after 3reboot windows seems to work fine
thx for your advices anyway