iv picked up this virus / spyware called pest catcher and despite several tries at catching it i cant remove it,ive tried spybot,spyware blaster,adaware,a squared trojan remover and several others but cant get rid of it, can anyone offer any advice please ?

What program alerted you to "Pest Catcher" in the first instance? And did it describe exactly what it was ie. a Trojan downloader, Worm, Virus etc.

If it's definitley a trojan or spyware then you should try AVG AntiSpyware?
It's probably the most thorough of the free antispyware programs in removing both Trojans and Spyware, I use Sbybot,Adaware and AVG. AVG tends to pick up everything that Spybot does and more. Spybot on the other hand misses some things that AVG picks up. All the Spyware applications are fully updated before I run any scan. AVG also do a very useful Anti Root kit which you should also install and run prior to any Anti Spyware scan.
If you don't know what a root kit is then read below:

"AVG Anti-Rootkit is a powerful tool with state-of-the-art technology for detection and removal of rootkits. Rootkits are used to hide the presence of a malicious object like trojans or keyloggers on your computer. If a threat uses rootkit technology to hide itself it is very hard to find the malware on your PC. AVG Anti-Rootkit gives you the power to find and delete the rootkit and to uncover the threat the rootkit is hiding."

Make sure you run a FULL AVG scan, and if it picks up the PEST then delete or quarantine it but you must make sure you run another scan immeadiately afterwards as some spyware can duplicate themselves and the duplicate may well be missed by the first pass. If the second pass detects something then delete or quaratine again and run another scan. I'd run the scan until I get at least 2 clean passes just to be on the safe side. Don't forget to download and install AVG Anti Root kit (From the same download page as AVG Spyware) and run the Anti Root kit BEFORE running your spyware scan.

http://free.grisoft.com/doc/5390/lng/us/tpl/v5#avg-anti-spyware-free

Turn of system restore n'all