Get the hell away from desktop PC support ESPECIALLY for a small company, messing around with virus killers etc. as sorry to say it but the impression is EVERYONE can do that (and install Microsoft Word, and install an extra 2gb of memory). The truth : 'Gary that makes my laptop mouse work if it goes funny' is the absolute bottom of the IT foodchain. and screwing around with PCs generally is the lowest paid of the low as basically all the kiddies want to do it .. and are prepared to do it for peanuts. It's seen (perhaps incorrectly) as easy work, the kind of work that the directors 15 year old cousin does for his home PC - so of course not worth paying any good money for.
Go for Unix Admin, or Oracle DBA, or 'C' programmer. That (full time) will at least get you to the low £40,000 levels minimum.
Don't even think about net development either. All the kiddies want to do that as well -- so competition means it's back down to a very cheap paying job. The impression rightly or wrongly is also that
anyone can hammer out a website, because there's thousands of very young men that can, and will, for peanuts!
Basically don't be scared of 'big bad corporate computer systems'. That's where the real money is. They're not more complex than PCs but all the kiddies (read under 24 year olds) are scared of them .. so the people who know how to do them can command at least 40K .. snd you don't even need to be particularly good. My client thinks I'm wonderful because I know about databases and unix, and 'Gary that fixes your mouse when it moves funny' is basically a neccessary evil - an annoying little geek which they'll be very pleasent to because he knows why your hard disk is making a wierd whining noise, but he's totally expendible, there are 2000 kids waiting to take his place that will require no training, will walk straight into the job, and are currently unemployed, so hell, keep him on no money. Why not?
Where as 'If Britboy leaves we're truly screwed because he's really good with our invoicing system which sounds hard so keep him sweet'!
Yes there is a lot of money in computers, but there's also a lot of money in stock room trading. You ask the guy in the trading room that makes the tea and fills up the printer with paper how much of the wodja he's seen...

Yet they'll call him a 'trading room assistant' because job titles are free to dole out and it makes him feel better so why not?